コミット: a89723ba66842646d5e548b0e4af9af878bb64c0 - jmr6805break (git)

およそ20年前に、68HC05 の開発の練習に書いた車のブレイクライト・方向指示器コントローラです。

コミットメタ情報

• リビジョン: a89723ba66842646d5e548b0e4af9af878bb64c0 (tree)
• 日時: 2013-07-08 22:34:06
• 作者: Joel Matthew Rees <reiisi@user...>
• コミッター: Joel Matthew Rees

ログメッセージ

Adding the assembler output files to the source tree, for reference.

変更サマリ

• add: TURNSIG.LST
• add: TURNSIG.MAP
• add: TURNSIG.S19

差分

--- /dev/null
+++ b/TURNSIG.LST
@@ -0,0 +1,1282 @@
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 1
+Turn Signal Switch by Joel Matthew Rees
+
+
+ 0200              1          PAGEWIDTH 128
+ 0200              2          HEADER 'Turn Signal Switch by Joel Matthew Rees'
+                   3  
+                   4  * Electronic Turn Signal and Emergency Flasher Switch/Timer
+                   5  *       Version 1.00
+                   6  *       Implemented on the 68HC705K1
+                   7  *       Assembled and tested on the M68HC705KICS
+                   8  *
+                   9  *       Copyright 1993 Joel Matthew Rees
+                  10  *
+                  11  *       Permission granted in advance for strictly non-profit
+                  12  * educational use.  All other rights retained by the author.
+                  13  
+                  14  * Authored by Joel Matthew Rees, June to November 1993
+                  15  *   of                                  also of
+                  16  *   South Salt Lake City                Amagasaki
+                  17  *   Utah                                Japan
+                  18  *   
+                  19  
+                  20  
+                  21  
+ 0200             22          SUBHEADER 'Purpose, Description, and Design'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 2
+Turn Signal Switch by Joel Matthew Rees
+Purpose, Description, and Design
+
+ 0200             22          PAGE
+                  23  * Design:
+                  24  
+                  25  *       When the turn signal and emergency flasher switch assembly on my
+                  26  * parents' 1971 Colt fell apart some years back, rather than go to the
+                  27  * nearest Dodge dealer in the next city to order the part, I designed a
+                  28  * substitute switch using a pair of double-pole, double-throw relays in
+                  29  * set-reset latch configuration.  Momentary-closed pushbuttons (mounted
+                  30  * to the steering column cover) set the turn signals, and a momentary
+                  31  * open pushbutton (mounted between the set buttons) or reed switch
+                  32  * (mounted inside the cover housing so a magnet mounted to the steering
+                  33  * column would actuate it) shut them off.  I usurped the emergency
+                  34  * flasher unit and took power from the battery lead on the ignition
+                  35  * switch, so when I needed emergency flashers, I could just turn both
+                  36  * turn signals on. Mom had trouble getting used to this arrangement, but
+                  37  * it passed Texas inspection in the seventies.
+                  38  
+                  39  *       Examining the 68HC05K series MCUs brought that turn signal
+                  40  * switch back to mind.  I thought ten bits of I/O, internal timers,
+                  41  * and the STOP mode would be sufficient to replicate the logic of that
+                  42  * switch assembly, adding directional turn signal return switches and
+                  43  * flasher and turn sgnal return logic as well.  It turned out to be a
+                  44  * tight squeeze.
+                  45  
+                  46  *       The intent of this document is to focus on the problems of
+                  47  * decoding inputs, directionalizing the turn signal return, eliminating
+                  48  * the flasher units, and minimizing power consumption using the STOP
+                  49  * mode and interrupts.  Hardware issues such as power supply design,
+                  50  * electro-static discharge protection (very important in automotive
+                  51  * applications), and details of lamp driver circuits are mostly set
+                  52  * aside.  The logic has been tested with the M68HC705KICS simulator
+                  53  * program, but has not been tested in a physical mock up or real
+                  54  * vehicle.  (I ran out of time for this project.)
+                  55  
+                  56  ******* Potential problems: ******************************************
+                  57  
+                  58  * I have not dealt with the problems that occur when the turn signals
+                  59  * are turned on while the return sensors are within range of their
+                  60  * actuator fields.  Two more bits of port B would have allowed complete
+                  61  * separation of the two functions.  A little extra code might allow
+                  62  * suppressing the turn signal inputs while both return switches are
+                  63  * active, to reduce the operator frustration factor.
+                  64  
+                  65  * I have also mostly ignored the problems presented by shorted switches.
+                  66  * Having the turn signal functions on port B is handy, because a week
+                  67  * turn signal spring will not keep the circuit from staying in the STOP
+                  68  * instruction.  Another 50 bytes of ROM might have allowed tracking time
+                  69  * of no change for every sensor, which could allow shutting out a
+                  70  * sensor that has been active more than n minutes.
+                  71  
+                  72  **********************************************************************
+                  73  
+                  74  *       One of the intents of this design was to replace mechanical
+                  75  * parts (that tend to flow in hot climates and become brittle in cold)
+                  76  * with logic.  In order to eliminate the mechanical latching lever with
+                  77  * spring loaded return, I have (perhaps arbitrarily) enforced a new "user
+                  78  * interface" involving momentary contact switches for the turn signals.
+                  79  * Two possible physical arrangements for the turn signal present
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 3
+Turn Signal Switch by Joel Matthew Rees
+Purpose, Description, and Design
+
+                  80  * themselves to my mind:  In the one, a spring-loaded, non-latching
+                  81  * signal rod (the latch/return mechanism was the weakest part) actuates
+                  82  * momentary contact switches in two axes; the rod can be pushed up or
+                  83  * down to activate the turn signals, or it can be pushed in to actuate
+                  84  * the manual cancel.  In another arrangement, the signal rod is fixed,
+                  85  * and three pushbuttons are provided on a pad at its end.  (Cancel in
+                  86  * the center would seem logical.)
+                  87  
+                  88  *       The emergency flasher switch is a momentary on pushbutton, and
+                  89  * it cancels itself in software -- push on, push off.  I think the audio
+                  90  * feedback and dash panel indicators should be sufficient user feedback.
+                  91  
+                  92  *       The turn signal return mechanism is a pair of reed relays
+                  93  * mounted inside the bottom of the steering column housing about 11.25
+                  94  * degrees apart, with one to four magnetic actuators distributed around
+                  95  * the steering shaft.  The shape, size, and position of the magnets and
+                  96  * reeds should be such that the reeds close only once as a magnet
+                  97  * passes, and such that the reeds have about 22.5 degrees of total
+                  98  * actuation. The overlap in actuation is used to determine the direction
+                  99  * the steering wheel is rotating.  Minor changes to the design should
+                 100  * allow the use of optical sensors, but I have the impression that
+                 101  * magnetic devices are more immune to extremes of climate.  (Maybe?)
+                 102  
+ 0200            103          SUBHEADER 'Model Schematic'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 4
+Turn Signal Switch by Joel Matthew Rees
+Model Schematic
+
+ 0200            103          PAGE
+                 104  *       An idealized schematic follows:
+                 105  
+                 106  
+                 107  * PA7>---FRNT_LEFT_DRVR---+---FL_SGNL_LAMP---GND
+                 108  *                         |
+                 109  *                         +---LEFT_INDCTR---GND
+                 110  *                         |
+                 111  *                         +---LEFT_AUDIO---GND
+                 112  
+                 113  * PA6>---FRNT_RGHT_DRVR---+---FR_SGNL_LAMP---GND
+                 114  *                         |
+                 115  *                         +---RGHT_INDCTR---GND
+                 116  *                         |
+                 117  *                         +---RGHT_AUDIO---GND
+                 118  
+                 119  * PA5>---REAR_LEFT_DRVR----RL_SGNL_LAMP---GND
+                 120  *
+                 121  * PA4>---REAR_RGHT_DRVR----RR_SGNL_LAMP---GND
+                 122  
+                 123  * PA3<---+---160K_OHM---------+---BRK_SW---12V
+                 124  *        |                    |
+                 125  *        +---5V_ZENER---GND   +---CENTER_BRK_LGHT---GND
+                 126  
+                 127  * PA2<---+---160K_OHM---ENGINE_ON_SW---12V
+                 128  *        |
+                 129  *        +---5V_ZENER---GND
+                 130  
+                 131  * PA1>---DRVRS_ON_CNTRL
+                 132  
+                 133  * IRQ<---+---100K_OHM---Vdd
+                 134  *        |
+                 135  *        +---EMG_SW---GND
+                 136  
+                 137  * PB1<>--+----------LEFT_RETURN_SW---+
+                 138  *        |                           |
+                 139  *        +---LEFT_TURN_SW---+        |
+                 140  *                           |        |
+                 141  *          Vdd---100K_OHM---+        |
+                 142  *                           |        |
+                 143  *        +---RGHT_TURN_SW---+        |
+                 144  *        |                           |
+                 145  * PB0<>--+----------RGHT_RETURN_SW---+
+                 146  *                                    |
+                 147  * PA0<---+---------------------------+
+                 148  *        |
+                 149  *        +---CAN_SW---100K_OHM---Vdd
+                 150  
+                 151  * RESET<---100K_OHM---Vdd
+                 152  
+                 153  * IF THIS IS IMPLEMENTED IN A REAL CIRCUIT, ESD PROTECTION MUST BE ADDED!
+                 154  
+ 0200            155          SUBHEADER 'Circuit Explication'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 5
+Turn Signal Switch by Joel Matthew Rees
+Circuit Explication
+
+ 0200            155          PAGE
+                 156  * Explanatory notes:
+                 157  
+                 158  *       PA1 allows the signal drivers to be shut down to preserve power.
+                 159  * I assume a suitable digital switch with power down is available.  If
+                 160  * optical sensors are used for the turn signal return, the optical
+                 161  * sources would also be turned on by this signal.  I assume it will be
+                 162  * active high.
+                 163  
+                 164  *       I arbitrarily assume the signal lamp drivers will be active low.
+                 165  * Who could say why?  It should be easy to find all references to the
+                 166  * driver lines with a text editor and reverse the active states of the
+                 167  * outputs.
+                 168  
+                 169  *       Hanging the indicators and the audio feedback on the front lamp
+                 170  * drivers separates them from brake activity.  Two audio feedback
+                 171  * devices are used here because there were not enough MCU outputs to
+                 172  * drive a single cheap clicking device.  Stereo audio feedback might be
+                 173  * a nice touch anyway, allowing a person with binaural hearing to
+                 174  * determine by sound which signal is on.  (If the ROM were a little
+                 175  * larger, a separate audio feedback could be modulated with different
+                 176  * sounds for left, right, and emergency flashers.)
+                 177  
+                 178  *       The center brake light is directly switched to eliminate one of
+                 179  * the separate high-power outputs. Fortunately, its state is not
+                 180  * dependent on any other inputs.
+                 181  
+                 182  *       The engine-on input (PA2) is necessary so that the MCU knows
+                 183  * when it can shut itself down to conserve power.  It is an interrupting
+                 184  * input so that the MCU STOP mode can be used.  Brake lights and
+                 185  * emergency flashers must be accessible when the engine is off, so those
+                 186  * inputs are also interrupting.  The engine-on and brake inputs are
+                 187  * naturally positive-going signals, but the emergency flasher input is
+                 188  * not naturally biased.  So the the emergency flasher seemed a more
+                 189  * natural match for IRQ.
+                 190  
+                 191  *       The following crude diagram illustrates the actuation in a left
+                 192  * rotation (restoring from a right turn or turning left).  The carots
+                 193  * indicate the position of the reed switches, the asterisks indicate the
+                 194  * actuation field of a magnet.
+                 195  
+                 196  *    Actuation Field ********
+                 197  *         Left Return Switch ^  ^ Right Return Switch
+                 198  *                      ********
+                 199  *                            ^  ^
+                 200  *                        ********
+                 201  *                            ^  ^
+                 202  *                          ********
+                 203  *                            ^  ^
+                 204  *                            ********
+                 205  *                            ^  ^
+                 206  *                              ********
+                 207  *                            ^  ^
+                 208  *                                ********
+                 209  *                            ^  ^
+                 210  
+                 211  *       Referring to the above diagram, the right turn signal return
+                 212  * switch is positioned about 5 5/8 degrees right of bottom center below
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 6
+Turn Signal Switch by Joel Matthew Rees
+Circuit Explication
+
+                 213  * the steering column and fixed to the steering column housing, and the
+                 214  * left return is positioned the same distance to the left.  In this way,
+                 215  * when the steering wheel rotates, the return switch for the direction
+                 216  * of rotation actuates first, then the opposite direction switch closes,
+                 217  * then the same direction switch opens, and then the opposite direction
+                 218  * switch opens.  Thus, when restoring from a turn, the return switch for
+                 219  * the direction of the turn closes after the other switch.  In other
+                 220  * words, if you turn right, the steering wheel will rotate to the left
+                 221  * when you return to straight, and the switches actuate from left to
+                 222  * right during the restore.  (I say this so many times because it takes
+                 223  * repeating to convince myself of it.)
+                 224  
+                 225  *       When both turn signals are off, both turn signal switch ports
+                 226  * are set as inputs.  When a turn signal switch input senses a closure,
+                 227  * its port is made an output and driven high.  Now, in addition to
+                 228  * manual cancel, the cancel port can sense steering wheel rotation.  In
+                 229  * same direction rotation, there is a lead period when the cancel input
+                 230  * does not remain high if the turn signal input ports' output states are
+                 231  * inverted.  The debounce routine suppresses cancel if this lead time is
+                 232  * sensed.
+                 233  
+                 234  *       Since the opposite direction turn signal switch port remains an
+                 235  * input, it can still be sensed.  The operator can change turn signals
+                 236  * directly, without hitting the cancel button.
+                 237  
+                 238  *       The separation of the switches and the actuation arc length I
+                 239  * specify are based on my assumption that the steering wheel will rotate
+                 240  * at a maximum speed of three revolutions per second, and that the four
+                 241  * to six mS (1 MHz crystal) required debounce period requires a minimum
+                 242  * 10 milli-second separate actuation period.  The actual result was 10.9
+                 243  * degrees separate actuation (21.8 total), which I arbitrarily rounded
+                 244  * up to a power of two fraction of the circle: 2*PI/16 total actuation
+                 245  * and 2*PI/32 separate actuation.
+                 246  
+                 247  *       A peculiar characteristic of this design is the apparent lack of
+                 248  * use for the RESET input.  Since power-on reset is built in to the
+                 249  * K-series MCUs, RESET should probably be tied high.  However, I suppose
+                 250  * it could make a good manual cancel-all input, if such is necessary.
+                 251  
+                 252  *       This assembler appears not to have a bit-not function for
+                 253  * operand expressions.  So, I have in several places resorted to the
+                 254  * obtuse expedient of exclusive-orring bits to be reset with $FF,
+                 255  * ergo,                 AND #{$FF ^ F_OPC ^ F_MNC}
+                 256  * instead of            AND #~(F_OPC | F_MNC)
+                 257  * which I think would have been clearer.
+                 258  
+                 259  *       One more assembler quirk -- I have used $FF in a couple of
+                 260  * places I would normally have used -1 to indicate all bits set.  The
+                 261  * assembler apparently turns {-1} into 1 in operands.
+                 262  
+ 0200            263          SUBHEADER 'Obligatory Mnemonics'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 7
+Turn Signal Switch by Joel Matthew Rees
+Obligatory Mnemonics
+
+ 0200            263          PAGE
+ 0200            264  $base   $0A
+ 0200            265  $include "68HC05K.EQU"
+                 266  
+ 0200            267          SUBHEADER 'Program Mnemonics'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 8
+Turn Signal Switch by Joel Matthew Rees
+Program Mnemonics
+
+ 0200            267          PAGE
+                 268  * physical I/O definitions
+                 269  * PORTA
+ 0200            270  F_LDRV  equ B7          ; four lamp drivers
+ 0200            271  F_LDRV_ equ B7_
+ 0200            272  F_RDRV  equ B6
+ 0200            273  F_RDRV_ equ B6_
+ 0200            274  R_LDRV  equ B5
+ 0200            275  R_LDRV_ equ B5_
+ 0200            276  R_RDRV  equ B4
+ 0200            277  R_RDRV_ equ B4_
+ 0200            278  DRVLMPS equ {F_LDRV | F_RDRV | R_LDRV | R_RDRV}
+ 0200            279  LFTDRV  equ {F_LDRV | R_LDRV}
+ 0200            280  RGTDRV  equ {F_RDRV | R_RDRV}
+ 0200            281  FRNTDRV equ {F_LDRV | F_RDRV}
+ 0200            282  REARDRV equ {R_LDRV | R_RDRV}
+ 0200            283  BRK_SW  equ B3
+ 0200            284  BRK_SW_ equ B3_
+ 0200            285  NGN_SW  equ B2          ; engine (ENG and EMG could be confusing)
+ 0200            286  NGN_SW_ equ B2_
+ 0200            287  DRVDRV  equ B1
+ 0200            288  DRVDRV_ equ B1_
+ 0200            289  EMG_BTF equ DRVDRV      ; where to fold EMG_BT
+ 0200            290  EMG_BTF_        equ DRVDRV_
+ 0200            291  CAN_BT  equ B0
+ 0200            292  CAN_BT_ equ B0_
+                 293  * PORTB
+ 0200            294  LFT_BT  equ B1  ; a handy data dependency! DO NOT CHANGE
+ 0200            295  LFT_BT_ equ B1_
+ 0200            296  RGT_BT  equ B0  ; another handy data dependency!
+ 0200            297  RGT_BT_ equ B0_
+                 298  * IRQ input (inverted) is the real EMG_BT
+                 299  
+                 300  
+                 301  * logical input definitions for debounce and states
+                 302  * bits are remapped for debounce and speed
+                 303  * six bits of physical input, high two bits borrowed for cancel logic
+ 0200            304  F_LFT   equ LFT_BT      ; another handy data dependency!
+ 0200            305  F_LFT_  equ LFT_BT_
+ 0200            306  F_RGT   equ RGT_BT      ; another handy data dependency!
+ 0200            307  F_RGT_  equ RGT_BT_
+ 0200            308  TURNSIG equ {F_LFT | F_RGT}
+ 0200            309  F_BRK   equ {BRK_SW < 2}        ; physical output bit
+ 0200            310  F_BRK_  equ {BRK_SW_ + 2}
+ 0200            311  F_NGN   equ {NGN_SW < 2}        ; physical output bit
+ 0200            312  F_NGN_  equ {NGN_SW_ + 2}
+ 0200            313  F_EMG   equ {DRVDRV < 2}        ; fold onto output bit
+ 0200            314  F_EMG_  equ {DRVDRV_ + 2}
+ 0200            315  ANYLITE equ {TURNSIG | F_BRK | F_EMG}
+ 0200            316  F_CAN   equ {CAN_BT < 2}
+ 0200            317  F_CAN_  equ {CAN_BT_ + 2}
+ 0200            318  F_OPC   equ $40                 ; opposite direction cancel record
+ 0200            319  F_MNC   equ $80                 ; manual cancel record
+                 320  
+                 321  *       The turn signal table and many of the turn signal routines
+                 322  * depend on F_LFT and F_RGT and LFT_BT and RGT_BT being in bits one and
+                 323  * zero (but not particular which is which!).  If these are changed,
+                 324  * there will be a domino effect on the rest of the code.
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 9
+Turn Signal Switch by Joel Matthew Rees
+Program Mnemonics
+
+                 325  
+ 0200            326          SUBHEADER 'Resource Definitions'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 10
+Turn Signal Switch by Joel Matthew Rees
+Resource Definitions
+
+ 0200            326          PAGE
+                 327  
+                 328  
+ 0200            329  XTAL    equ 1   ; crystal frequency, in MHz
+ 0200            330  RTIPOW  equ 0
+                 331  *       1   ; bits 1 & 0 for timer hardware
+ 0200            332  RTIRATE equ {2 < RTIPOW}        ; 2 ^ RTIPOW
+ 0200            333  TIMOUT  equ 1
+                 334  *       {9155*XTAL/RTIRATE+1}       ; 5 minutes (if XTAL equ is correct)
+                 335  * only one flash rate, 2/3 duty cycle
+ 0200            336  FLASH0  equ 1
+                 337  *       {32*XTAL/RTIRATE/4}         ; about 1/4 second off time
+ 0200            338  FLASH1  equ 1
+                 339  *       {32*XTAL/RTIRATE/2}         ; about 1/2 second on time
+                 340  
+ 0017            341          org MOR
+                 342  * Software Pulldown is used.
+                 343  * Can't spare the third RC oscillator pin.
+                 344  * Set RC because we assume the cheap oscillator.
+                 345  * STOP must not convert to WAIT: saves power when engine off.
+                 346  * Assume Low Voltage Reset would be meaningless.
+                 347  * PA3 - PA0 interrupts are used to bring the chip up for brake, engine on.
+                 348  * Accept level sensitive interrupts, since IRQ is disabled immediately.
+                 349  * Assume COP might be useful here.
+ 0017 27         350          fcb {RC | PIRQ | LEVEL | COPEN}
+                 351  
+ 00E0            352          org RAMBEG
+ 00E0            353  DEBO    rmb 3   ; the debounce record chain
+ 00E3            354  SSTBLE  rmb 1   ; temporary record of stable bits
+ 00E4            355  TOGGLE  rmb 1   ; record of toggles
+ 00E5            356  ISTATE  rmb 1   ; record of the current input state
+ 00E6            357  STATES  rmb 1   ; current controller states
+ 00E7            358  NGN_TIM rmb 2   ; engine time out timer
+ 00E9            359  FLASH   rmb 1   ; flash timer
+ 00EA            360  FLDARK  rmb 1   ; flash light or dark state, 11111111 == dark
+ 00EB            361  FLMASK  rmb 1   ; flash mask to communicate between BRK, EMG, and TRN
+ 00EC            362  TMPTRN  rmb 1   ; temporary for keep turn signal interpretation
+ 00ED            363  LASTST  rmb 1   ; previous state record to separate timer from decode
+ 00EE            364          rmb 4
+ 00F2            365  DBGCT   rmb 4   ; count how many times TIMSRV has executed
+                 366  
+                 367  
+                 368  * ROM definitions follow:
+ 0200            369          org ROMBEG
+                 370  
+ 0200            371          SUBHEADER 'Timer Service Code'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 11
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code
+
+ 0200            371          PAGE
+                 372  
+                 373  *       The timer service routine has these functions: debouncing the
+                 374  * inputs, flagging changes in TOGGLE, adjusting STATES to match the
+                 375  * inputs, and maintaining two software clocks. Interrupts occur on timer
+                 376  * overflow (1024 CPU cycles).
+                 377  
+                 378  *       The debounce routine translates the physical inputs to logical
+                 379  * inputs, maintains a record of the last three logical states sensed in
+                 380  * DEBO, debounces (in parallel) each input on three identical states,
+                 381  * flags changes in the debounced input in TOGGLE, and leaves the current
+                 382  * debounced input in ISTATE.  Since debouncing occurs on three identical
+                 383  * states, the debounce period is between two and three timer overflows
+                 384  * -- 4 to 6 mS with a 1 MHz crystal, 2 to 3 mS with a 2 MHz crystal.
+                 385  
+                 386  *       This debounce technique works because we don't care what is
+                 387  * happening to the inputs between timer overflows, and because we assume
+                 388  * there is no physical mechanism to induce noise coincident and rythmic
+                 389  * with timer overflow.
+                 390  
+                 391  *       The TOGGLE cancel (F_CAN) bit is suppressed on same-direction
+                 392  * rotation. Trailing edge TOGGLE F_CAN and F_EMG are filtered out to
+                 393  * simplify interpretation of those functions.  Opposite direction cancel
+                 394  * (F_OPC) and manual cancel (F_MNC) ISTATE auxiliary flags are
+                 395  * maintained to provide information on the source of the F_CAN bit, and
+                 396  * are always filtered out of TOGGLE and STATES.  STATES F_CAN is
+                 397  * adjusted according to TOGGLE F_CAN rather than ISTATE F_CAN, by which
+                 398  * means we hope to not need to remember in which direction a cancel was
+                 399  * sensed.  In other words, we hope that F_CAN does not toggle again
+                 400  * until both return sensors are past the actuator field.
+                 401  
+                 402  *       After adding an event queue and checking the timing results, two
+                 403  * things became clear: there is plenty of time to handle all the changes
+                 404  * to STATES without a queue, and TOGGLE makes a sort of horizontal
+                 405  * priority queue anyway.  In other words, there is no reason to make the
+                 406  * adjustments to STATES asynchronous when there is plenty of headroom
+                 407  * for synchronous adjustments.  Moreover, the adjustments take less time
+                 408  * than organizing the button events in a queue.  (Darn!  I was kind of
+                 409  * proud of that six byte queue, and the shift technique for storing
+                 410  * events into it.)
+                 411  
+                 412  *       When moving the ISTATE turn signal bits to STATES, the STATES
+                 413  * turn signal bits are examined to see if the direction has changed.  If
+                 414  * a STATE turn signal bit is on, PORTB is set to wait for F_CAN.
+                 415  
+                 416  *       The engine time-out counter communicates with the power down
+                 417  * routine via the STATES engine on (F_NGN) bit.  In other words, STATES
+                 418  * F_NGN bit is held off until the ISTATE F_NGN bit and the STATES F_EMG
+                 419  * and F_BRK bits have been inactive for five minutes.  (This perhaps
+                 420  * overloads the semantics of STATES F_NGN.)
+                 421  
+                 422  *       In the current design, the turn signals are not masked with the
+                 423  * ISTATE F_NGN bit, and so will function during the time-out period.
+                 424  * This "feature" can easily be corrected in the debounce routine.
+                 425  
+                 426  *       It should be relatively easy to add a turn signal time-out
+                 427  * counter to turn off the turn signals after the same turn signal has
+                 428  * been on an un-reasonable period, such as five or more minutes.
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 12
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code
+
+                 429  * Such a time-out might negatively impact safety when attempting to turn
+                 430  * in backed-up traffic or onto a very busy highway, or when using the
+                 431  * turn signal to show a car parked for delivery, etc.  It also might
+                 432  * cause drivers to become even lazier.
+                 433  
+                 434  *       Both timers reset in such a manner as to be in a known state at
+                 435  * any time they are put into use.
+                 436  
+                 437  *       The single emergency and turn signal signal flasher uses a single
+                 438  * rate and duty cycle.
+                 439  
+ 0200            440          SUBHEADER 'Timer Service Code -- Debounce and Toggle Filter'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 13
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Debounce and Toggle Filter
+
+ 0200            440          PAGE
+                 441  
+ 0200 83         442          swi     ; since we have a few unused ROM locations
+ 0201 83         443          swi
+ 0202 83         444          swi
+                 445  
+ 0203            446  $CYCLE_ADDER_ON
+ 0203 1608       447  TIMSRV  bset TOFR_,TSCR
+                 448  
+                 449  * move the debounce chain
+ 0205 B6E1       450          lda DEBO+1
+ 0207 B7E2       451          sta DEBO+2
+ 0209 B6E0       452          lda DEBO
+ 020B B7E1       453          sta DEBO+1
+                 454  
+                 455  * record previous STATE
+ 020D B6E6       456          lda STATES
+ 020F B7ED       457          sta LASTST
+                 458  
+                 459  * read the static inputs, converting physical to logical
+ 0211 B600       460          lda PORTA
+ 0213 A40D       461          and #{BRK_SW | NGN_SW | CAN_BT}         ; clears DRV_DRV
+ 0215 2F02       462          bih TMIEMG      ; invert EMG and fold it in
+ 0217 AA02       463          ora #EMG_BTF    ; keep temporally very close to first read
+ 0219            464  TMIEMG  equ *
+ 0219 48         465          lsla    ; remap
+ 021A 48         466          lsla
+ 021B B7E0       467          sta DEBO
+ 021D B601       468          lda PORTB       ; PB2-7 always read 0
+ 021F BAE0       469          ora DEBO
+ 0221 B7E0       470          sta DEBO
+                 471  
+                 472  * read the turn signal return and manual cancel auxiliary flags
+                 473  * (F_CAN & turn_sig_on) <=> read auxiliary flags
+                 474  * Assume that DDRB showing output means turn signal on and waiting
+                 475  * for cancel.
+                 476  * Filtering F_CAN on same-direction turn is handled later.
+                 477  * Remember that F_CAN should be sensed via TOGGLE, to avoid multiple
+                 478  * interpretations of one pass of the actuator.
+                 479  
+ 0223 A504       480          bit #F_CAN      ; nothing at all without cancel
+ 0225 2725       481          beq TM0TURN
+ 0227 BE05       482          ldx DDRB        ; cancel meaningless if not waiting for it
+ 0229 2721       483          beq TM0TURN
+TOTAL CYCLES = 0 decimal
+ 022B            484  $CYCLE_ADDER_OFF
+ 022B            485  $CYCLE_ADDER_ON
+ 022B 9F         486          txa
+ 022C A803       487          eor #{LFT_BT | RGT_BT}  ; strobe other side
+ 022E B701       488          sta PORTB       ; set output state first
+ 0230 B705       489          sta DDRB        ; handy (data dependent) output state, huh?
+ 0232 000000     490          brset CAN_BT_,PORTA,TMTBIT6     ; CAN_BT_ into carry
+ 0235 46         491  TMTBIT6 rora    ; carry into bit 7
+ 0236 3F05       492          clr DDRB        ; kill strobe: manual cancel?
+ 0238 000000     493          brset CAN_BT_,PORTA,TMTBIT7     ; CAN_BT_ into carry again
+ 023B 46         494  TMTBIT7 rora    ; carry into bit 7 again
+ 023C A4C0       495          and #{F_OPC | F_MNC}
+ 023E BAE0       496          ora DEBO
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 14
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Debounce and Toggle Filter
+
+ 0240 A540       497          bit #F_OPC      ; ignore turn signals if opposition cancel
+ 0242 2702       498          beq TMTNTN
+ 0244 A4FC       499          and #{$FF ^ TURNSIG}
+ 0246 B7E0       500  TMTNTN  sta DEBO
+ 0248 BF01       501          stx PORTB       ; restore turn signal inputs
+ 024A BF05       502          stx DDRB
+ 024C            503  TM0TURN equ *
+                 504  * leave A == DEBO
+TOTAL CYCLES = 0 decimal
+ 024C            505  $CYCLE_ADDER_OFF
+ 024C            506  $CYCLE_ADDER_ON
+                 507  
+                 508  * debounce inputs, set flags in TOGGLE and ISTATE
+                 509  * STABLE_BITS = ~((DEBO[0] ^ DEBO[1]) | (DEBO[1] ^ DEBO[2]))
+                 510  * A == DEBO on entry
+ 024C B8E1       511          eor DEBO+1
+ 024E B7E4       512          sta TOGGLE      ; re-use TOGGLE, TOGGLE not valid
+ 0250 B6E1       513          lda DEBO+1
+ 0252 B8E2       514          eor DEBO+2
+ 0254 BAE4       515          ora TOGGLE      ; a bit for any input that bounced
+ 0256 43         516          coma            ; bits that bounced are clear
+ 0257 97         517          tax             ; STABLE_BITS
+ 0258 B4E0       518          and DEBO        ; state of stable bits
+ 025A B7E3       519          sta SSTBLE      ; (unstable bits still clear)
+ 025C 9F         520          txa
+ 025D B4E5       521          and ISTATE      ; look only at bits that are stable
+ 025F B8E3       522          eor SSTBLE      ; flag bits that toggled
+ 0261 B7E4       523          sta TOGGLE      ; true TOGGLEs, but not yet filtered
+ 0263 43         524          coma            ; mask of non-toggles
+ 0264 B4E5       525          and ISTATE      ; old state of non-toggles
+ 0266 B7E5       526          sta ISTATE      ; (toggled bits cleared)
+ 0268 B6E4       527          lda TOGGLE      ; mask of toggles
+ 026A B4E3       528          and SSTBLE      ; new states of bits that toggled
+ 026C BAE5       529          ora ISTATE
+ 026E B7E5       530          sta ISTATE      ; ISTATE now has current debounced inputs
+                 531  * leave A == ISTATE
+                 532  
+                 533  * filter out TOGGLE F_CAN if same direction
+                 534  * A == ISTATE on entry
+ 0270 A5C0       535          bit #{F_OPC | F_MNC}    ; opposite direction or manual?
+ 0272 2602       536          bne TMF1CAN
+ 0274 15E4       537          bclr F_CAN_,TOGGLE      ; same direction
+ 0276            538  TMF1CAN equ *
+                 539  * leave A == ISTATE
+                 540  
+                 541  * filter out trailing edge of F_EMG and F_CAN in TOGGLE
+                 542  * also filter out auxiliary TOGGLEs in passing
+                 543  * ISTATE == A on entry
+ 0276 AA33       544          ora #{F_NGN | F_BRK | F_LFT | F_RGT}    ; not filtered
+ 0278 B4E4       545          and TOGGLE      ; filter (logical) fall(en) edges
+ 027A A43F       546          and #{$FF ^ F_OPC ^ F_MNC}      ; auxiliaries should never TOGGLE
+ 027C B7E4       547          sta TOGGLE
+                 548  * leave A == TOGGLE
+                 549  
+ 027E            550          SUBHEADER 'Timer Service Code -- Adjust STATES'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 15
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Adjust STATES
+
+ 027E            550          PAGE
+                 551  
+                 552  * move brake bit from ISTATE to STATES
+ 027E 1BE6       553          bclr F_BRK_,STATES
+ 0280 0BE502     554          brclr F_BRK_,ISTATE,TMF0BRK
+ 0283 1AE6       555          bset F_BRK_,STATES
+ 0285            556  TMF0BRK equ *
+                 557  
+                 558  * toggle STATES F_EMG if TOGGLE F_EMG
+                 559  * act on TOGGLE to avoid multiple reads of EMG button
+ 0285 07E406     560          brclr F_EMG_,TOGGLE,TMF0EMG
+ 0288 B6E6       561          lda STATES
+ 028A A808       562          eor #F_EMG
+ 028C B7E6       563          sta STATES      ; STATES not yet valid!
+ 028E            564  TMF0EMG equ *
+ 028E 201A       565          bra TMSTRN      ; skip over the turn signal states table
+                 566  * leaves A indeterminate
+                 567  
+ 0290 83         568          swi     ; since we have a few unused ROM locations
+ 0291 83         569          swi
+ 0292 83         570          swi
+ 0293 83         571          swi
+ 0294 83         572          swi
+                 573  
+                 574  * this table is very data dependent
+ 0295            575  TURNSTATE       equ *   ; depends on turn signals being rightmost
+                 576  *            S'                   S  I
+ 0295 00         577          fcb %00                 ; 00 00
+ 0296 01         578          fcb %01                 ; 00 01
+ 0297 02         579          fcb %10                 ; 00 10
+ 0298 08         580          fcb {%00 | F_EMG}       ; 00 11 set F_EMG instead
+ 0299 01         581          fcb %01                 ; 01 00
+ 029A 01         582          fcb %01                 ; 01 01
+ 029B 02         583          fcb %10                 ; 01 10 should not occur
+ 029C 02         584          fcb %10                 ; 01 11 this inverts directions
+ 029D 02         585          fcb %10                 ; 10 00
+ 029E 01         586          fcb %01                 ; 10 01 should not occur
+ 029F 02         587          fcb %10                 ; 10 10
+ 02A0 01         588          fcb %01                 ; 10 11 this inverts directions
+ 02A1 00         589          fcb %00                 ; 11 00 should not occur
+ 02A2 01         590          fcb %01                 ; 11 01 should not occur
+ 02A3 02         591          fcb %10                 ; 11 10 should not occur
+ 02A4 00         592          fcb %00                 ; 11 11 should not occur
+                 593  * Since PEPROM accesses only one bit at a time,
+                 594  * and since I can't figure out how to build the turn signal new state
+                 595  * table in the PEPROM as part of this file anyway,
+                 596  * and since we apparently have plenty of ROM,
+                 597  * I decided this table is not a good candidate for the PEPROM.
+                 598  * Darn!
+                 599  * After careful consideration, I decided this table does not benefit
+                 600  * from a more symbolic construction.  As it stands, it does not matter
+                 601  * whether F_LFT or F_RGT is b0, only that they do reside in B0 and B1.
+                 602  
+ 02A5 83         603          swi     ; since we have a few unused ROM locations
+ 02A6 83         604          swi
+ 02A7 83         605          swi
+ 02A8 83         606          swi
+ 02A9 83         607          swi
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 16
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Adjust STATES
+
+                 608  
+                 609  * turn on STATES turn signal if ISTATE turn signal is on
+                 610  * check to see if direction has changed
+ 02AA B6E6       611  TMSTRN  lda STATES
+ 02AC A403       612          and #TURNSIG
+ 02AE 48         613          lsla
+ 02AF 48         614          lsla
+ 02B0 B7EC       615          sta TMPTRN
+ 02B2 B6E5       616          lda ISTATE
+ 02B4 A403       617          and #TURNSIG
+ 02B6 BAEC       618          ora TMPTRN
+ 02B8 97         619          tax
+ 02B9 D60295     620          lda TURNSTATE,x
+ 02BC B7EC       621          sta TMPTRN
+ 02BE B6E6       622          lda STATES
+ 02C0 A4FC       623          and #{$FF ^ TURNSIG}
+ 02C2 BAEC       624          ora TMPTRN      ; table is 0s in b2-7, except forced F_EMG
+ 02C4 B7E6       625          sta STATES      ; may be reset by F_CAN
+                 626  * leaves A == STATES
+                 627  
+                 628  * cancel STATES turn signal if TOGGLE F_CAN is not filtered out
+                 629  * Act on TOGGLE to avoid multiple reads of single actuator pass!
+                 630  * A == STATES on entry
+ 02C6 05E404     631          brclr F_CAN_,TOGGLE,TMCAN0
+ 02C9 A4FC       632          and #{$FF ^ TURNSIG}
+ 02CB B7E6       633          sta STATES      ; STATES not yet valid!
+ 02CD            634  TMCAN0  equ *           ; turn signals are valid
+                 635  * leaves A == STATES
+                 636  
+                 637  * Now we should have no more than one turn signal on.
+                 638  * set up steering wheel return sense state or clear it
+                 639  * then latch turn signal input to keep it from reverting
+                 640  * A == STATES on entry
+ 02CD A403       641          and #TURNSIG
+ 02CF B701       642          sta PORTB       ; another handy value dependency!
+ 02D1 B705       643          sta DDRB        ; gate it out, if there
+                 644  * I feel there is a better way, but I'm out of time
+ 02D3 B7EC       645          sta TMPTRN      ; feed response back
+ 02D5 B6E5       646          lda ISTATE
+ 02D7 A4FC       647          and #{$FF ^ TURNSIG}
+ 02D9 BAEC       648          ora TMPTRN
+ 02DB B7E5       649          sta ISTATE
+                 650  * leaves A == ISTATE
+                 651  
+                 652  * if not timed out, STATES F_NGN should not yet be clear!
+ 02DD B6E8       653          lda NGN_TIM+1
+ 02DF BAE7       654          ora NGN_TIM
+ 02E1 2602       655          bne TMFNGN0
+ 02E3 18E6       656          bset F_NGN_,STATES       ; might time out before RTI
+ 02E5            657  TMFNGN0 equ *
+                 658  
+                 659  * STATES is still not valid!
+                 660  * fall through to TMCLOCK
+                 661  
+ 02E5            662          SUBHEADER 'Timer Service Code -- Engine Time Out and Flasher Timers'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 17
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Engine Time Out and Flasher Timers
+
+ 02E5            662          PAGE
+                 663  
+                 664  * reset engine time-out if F_NGN, F_EMG, or F_BRK TOGGLEs
+ 02E5 B6E4       665  TMCLOCK lda TOGGLE
+ 02E7 A438       666          and #{F_NGN | F_EMG | F_BRK}
+ 02E9 2708       667          beq TMORST
+ 02EB A601       668          lda #{TIMOUT & $FF }    ; reset value low byte
+ 02ED B7E8       669          sta NGN_TIM+1
+ 02EF A601       670          lda #{TIMOUT / $100 + 1}        ; borrow on 0, not -1
+ 02F1 B7E7       671          sta NGN_TIM
+ 02F3            672  TMORST  equ *
+                 673  
+                 674  * if flashers TOGGLE off, reset the flashers
+                 675  * if they TOGGLE on, clear the mask only if none on before
+ 02F3 A60B       676          lda #{F_EMG | TURNSIG}
+ 02F5 B5E4       677          bit TOGGLE
+ 02F7 2714       678          beq TMSCLK
+ 02F9 B5E6       679          bit STATES      ; flasher active?
+ 02FB 260A       680          bne TMMFLH
+ 02FD A6FF       681          lda #$FF        ; reset flash timer
+ 02FF B7EA       682          sta FLDARK
+ 0301 A601       683          lda #FLASH1
+ 0303 B7E9       684          sta FLASH
+ 0305 2006       685          bra TMSCLK
+                 686  
+ 0307 B5ED       687  TMMFLH  bit LASTST      ; flashers already running?
+ 0309 2602       688          bne TMMFLH0     ; might be better to shine on every change?
+ 030B 3FEA       689          clr FLDARK
+ 030D            690  TMMFLH0 equ *
+                 691  
+                 692  *       Although the Real Time Interrupt is masked, the software clocks
+                 693  * clock on the RTI flag.  See RTIPOW for the RTI flag rate
+                 694  
+ 030D 0D082D     695  TMSCLK  brclr RTIF_,TSCR,TIMDUN
+ 0310 1408       696          bset RTIFR_,TSCR
+                 697  
+                 698  *       Engine time-out counter only runs when the ISTATE F_NGN bit is
+                 699  * low and the emergency flashers and brakes (STATES F_EMG and F_BRK) are
+                 700  * with power down routine via STATES F_NGN.
+                 701  
+ 0312 08E514     702          brset F_NGN_,ISTATE,TMNGNR0
+ 0315 B6E6       703          lda STATES
+ 0317 A438       704          and #{F_NGN | F_EMG | F_BRK}    ; brakes or emg flashers?
+ 0319 A810       705          eor #F_NGN                      ; already counted out?
+ 031B 260C       706          bne TMNGNR0
+ 031D 3AE8       707          dec NGN_TIM+1
+ 031F 2608       708          bne TMNGNR0      ; initial count is adjusted to make this work
+ 0321 3AE7       709          dec NGN_TIM
+ 0323 2604       710          bne TMNGNR0
+ 0325 19E6       711          bclr F_NGN_,STATES      ; signal timed out
+ 0327 18E4       712          bset F_NGN_,TOGGLE      ; communicate change to STATES F_NGN
+ 0329            713  TMNGNR0 equ *   ; Only now is STATES valid!
+                 714  
+                 715  *       The flasher counter runs only when STATES F_EMG, F_LFT, or F_RGT
+                 716  * are set.  When there are no flashers running, FLDARK is set, causing
+                 717  * FLASH1 (on time) to be loaded when when flasher timer starts.
+                 718  
+ 0329 A60B       719  TMFLASH lda #{F_EMG | TURNSIG}
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 18
+Turn Signal Switch by Joel Matthew Rees
+Timer Service Code -- Engine Time Out and Flasher Timers
+
+ 032B B5E6       720          bit STATES      ; flasher active?
+ 032D 270E       721          beq TMFLH0
+ 032F 3AE9       722          dec FLASH
+ 0331 260A       723          bne TMFLH0
+ 0333 A601       724          lda #FLASH1
+ 0335 33EA       725          com FLDARK
+ 0337 2A02       726          bpl TMFLTM      ; result dark (1s) or light (0s)
+ 0339 A601       727          lda #FLASH0
+ 033B B7E9       728  TMFLTM  sta FLASH
+ 033D            729  TMFLH0  equ *
+                 730  
+                 731  *       It might be amusing to install a turn signal time out so that if
+                 732  * the turn signals remain flashing for more than ten minutes, they turn
+                 733  * themselves off.  The entire mechanism should fit here.  As mentioned
+                 734  * above, consider safety first!
+                 735  
+                 736  TIMDUN
+ 033D 3CF5       737          inc DBGCT+3     ; count number of timer interrupts serviced
+ 033F 260A       738          bne TIMDUX      ; put here strictly for debugging sessions
+ 0341 3CF4       739          inc DBGCT+2     ; so I can have an idea of virtual time
+ 0343 2606       740          bne TIMDUX
+ 0345 3CF3       741          inc DBGCT+1
+ 0347 2602       742          bne TIMDUX
+ 0349 3CF2       743          inc DBGCT
+                 744  TIMDUX
+ 034B 120A       745          bset IRQR_,ISCR ; POTA and IRQ activity may set IRQF
+ 034D 80         746          rti
+TOTAL CYCLES = 0 decimal
+ 034E            747  $CYCLE_ADDER_OFF
+                 748  
+ 034E 83         749          swi     ; more unused ROM
+ 034F 83         750          swi
+ 0350 83         751          swi
+ 0351 83         752          swi
+ 0352 83         753          swi
+ 0353 83         754          swi
+ 0354 83         755          swi
+                 756  
+ 0355            757          SUBHEADER 'Initializations'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 19
+Turn Signal Switch by Joel Matthew Rees
+Initializations
+
+ 0355            757          PAGE
+                 758  
+                 759  * waking up simply resets the MCU
+                 760  * if SWI occurs, the machine is not in a defined state, and must reset
+                 761  IRQSRV
+                 762  SWISRV
+ 0355 AE5C       763          ldx #$5C        ; unique
+ 0357 CF03F0     764          stx COPR
+ 035A 9C         765          rsp     ; now falls through to RSTSRV
+ 035B 120A       766          bset IRQR_,ISCR ; it just gets us started
+                 767  
+                 768  * general inits
+                 769  RSTSRV
+                 770  * disable external interrupts
+ 035D 1F0A       771          bclr IRQE_,ISCR ; disable external interrupts
+ 035F 120A       772          bset IRQR_,ISCR ; clear the external interrupt flag
+                 773  * get ports stared right
+ 0361 A6F0       774          lda #DRVLMPS
+ 0363 B700       775          sta PORTA       ; initial output values
+ 0365 A6F2       776          lda #{DRVLMPS | DRVDRV}
+ 0367 B704       777          sta DDRA        ; set up directions
+ 0369 B710       778          sta PDRA        ; pull downs only on inputs
+ 036B 3F01       779          clr PORTB       ; initial outputs (do port B just in case)
+ 036D 3F05       780          clr DDRB        ; B initially input
+ 036F 3F11       781          clr PDRB        ; with pull downs set
+                 782  * make sure EPROM programming stuff is out of the way
+                 783  *        clr EPROG       ; ICS05K complains, skip by hand
+ 0371 3F0F       784          clr PESCR
+                 785  * set up specific variables
+ 0373 A610       786          lda #F_NGN      ; pretend the engine is on, to get us started
+ 0375 B7E0       787          sta DEBO        ; start debounce chain clear
+ 0377 B7E1       788          sta DEBO+1      ; DEBO+2 is thrown out on first timer interrupt
+ 0379 B7E6       789          sta STATES      ; no unknown states
+ 037B B7E5       790          sta ISTATE
+ 037D A601       791          lda #{TIMOUT & $FF }            ; reset time-out low byte
+ 037F B7E8       792          sta NGN_TIM+1
+ 0381 A601       793          lda #{TIMOUT / $100 + 1}        ; counter borrows on 0, not -1
+ 0383 B7E7       794          sta NGN_TIM
+ 0385 A6FF       795          lda #$FF
+ 0387 B7EA       796          sta FLDARK      ; initial flash state is dark
+ 0389 A601       797          lda #FLASH1
+ 038B B7E9       798          sta FLASH       ; initial flash time is on/light state
+                 799  * clear the virtual debugging time counter
+ 038D 3FF2       800          clr DBGCT
+ 038F 3FF3       801          clr DBGCT+1
+ 0391 3FF4       802          clr DBGCT+2
+ 0393 3FF5       803          clr DBGCT+3
+                 804  * set up hardware timer
+ 0395 AE6A       805          ldx #$6A        ; unique use of X
+ 0397 CF03F0     806          stx COPR        ; b0 clear, about to change timer rate
+ 039A A600       807          lda #{RTIPOW}   ; set rate
+ 039C B708       808          sta TSCR
+ 039E AA0C       809          ora #{TOFR | RTIFR}     ; clear pending interrupts
+ 03A0 B708       810          sta TSCR
+ 03A2 1A08       811          bset TOIE_,TSCR ; first section overflow interrupt only
+                 812  
+                 813  * Falls through to DOSTATES
+                 814  
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 20
+Turn Signal Switch by Joel Matthew Rees
+DOSTATES: Interpret States
+
+ 03A4            815          SUBHEADER 'DOSTATES: Interpret States'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 21
+Turn Signal Switch by Joel Matthew Rees
+DOSTATES: Interpret States
+
+ 03A4            815          PAGE
+                 816  
+                 817  *       The debounce and timer routines make the output state machine
+                 818  * simple.  All indicator lamps are set according to the indicator STATES,
+                 819  * then masked by the current flasher output state (FLDARK).  Then, if the
+                 820  * brake light STATES bit is set, the rear lamps are forced on.  Then,
+                 821  * DRVDRV is only set if lamps are on (to save power when the engine is
+                 822  * off).
+                 823  
+                 824  *       Finally, if STATES F_NGN bit is clear, the power-down routine is
+                 825  * executed (and never returned from).  Again, requiring the time-out
+                 826  * counter to hold off the STATES engine-on bit may be a bit of a
+                 827  * semantic overload, but it seems more natural than making the STATES
+                 828  * F_NGN bit a mere mirror of ISTATE F_NGN, and then maintaining a
+                 829  * separate flag which would operate by the same rules as STATES F_NGN
+                 830  * does in the present design.  It also seems less data coupled than
+                 831  * having the power-down sense routine examine the internals of the
+                 832  * counter.
+                 833  
+                 834  *       FLDARK is used slightly ambiguously:  in the flasher timer
+                 835  * routine, bit 7 is used to determine whether to use the on period or
+                 836  * off period.  In the output state machine, below, all lamp bits are
+                 837  * used to mask out the signal lamps when the flasher says they should be
+                 838  * dark.  Rather than concern myself in several places with the state of
+                 839  * non-lamp bits, I mask them out where they could cause trouble.
+                 840  
+                 841  DOSTATES:
+ 03A4 8F         842          wait    ; wait for something intelligible to debounce
+ 03A5 AE78       843          ldx #$78        ; unique
+ 03A7 CF03F0     844          stx COPR        ; tell COP we're in control
+                 845  
+                 846  * update the (inverted) lamp output state
+ 03AA A6F0       847          lda #DRVLMPS    ; guess nothing shines (inverted drive)
+                 848  * A == lamp output state
+                 849  
+                 850  * now mask in inverted drive bits for any flashers that are on
+ 03AC 07E602     851          brclr F_EMG_,STATES,STT0EMG
+ 03AF A40F       852          and #{$FF ^ DRVLMPS}
+ 03B1            853  STT0EMG equ *
+                 854  * A == lamp output state
+                 855  
+ 03B1 03E602     856          brclr F_LFT_,STATES,STT0LFT
+ 03B4 A45F       857          and #{$FF ^ LFTDRV}
+ 03B6            858  STT0LFT equ *
+                 859  * A == lamp output state
+                 860  
+ 03B6 01E602     861          brclr F_RGT_,STATES,STT0RGT
+ 03B9 A4AF       862          and #{$FF ^ RGTDRV}
+ 03BB            863  STT0RGT equ *
+                 864  * A == lamp output state
+                 865  
+                 866  * mask out flasher lamps if flasher is in off state
+ 03BB BAEA       867          ora FLDARK
+                 868  * A == lamp output state
+                 869  
+                 870  * check for brake lights
+ 03BD 0BE602     871  STTBRK  brclr F_BRK_,STATES,STT0BRK
+ 03C0 A4CF       872          and #{$FF ^ REARDRV}    ; brake has higher priority than flash
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 22
+Turn Signal Switch by Joel Matthew Rees
+DOSTATES: Interpret States
+
+ 03C2            873  STT0BRK equ *
+                 874  * A == lamp output state
+                 875  
+ 03C2 A4F0       876          and #DRVLMPS    ; filter out extraneous bits
+ 03C4 B7EB       877          sta FLMASK
+ 03C6 A8F0       878          eor #DRVLMPS    ; any lamps driven?
+ 03C8 2702       879          beq STT0FLH     ; invert the CCR zero bit and move it to DRVDRV
+ 03CA 12EB       880          bset DRVDRV_,FLMASK
+ 03CC            881  STT0FLH equ *
+                 882  * now A is free
+                 883  
+ 03CC B600       884          lda PORTA
+ 03CE A40D       885          and #{$FF ^ DRVLMPS ^ DRVDRV}
+ 03D0 BAEB       886          ora FLMASK
+ 03D2 B700       887          sta PORTA
+                 888  
+                 889  * all done with lamps until next timer interrupt
+                 890  * loop to wait if engine not timed-out
+ 03D4 08E6CD     891          brset F_NGN_,STATES,DOSTATES
+                 892  
+                 893  * At this point, we know there has been no engine, emergency flasher, or
+                 894  * brake activity for about five minutes.
+                 895  
+                 896  * go to power conserving state
+                 897  * first shut down all lamps
+ 03D7 A6F0       898          lda #DRVLMPS    ; DRVDRV, CAN_BT also off!
+                 899  * should be     lda #{DRVLMPS & ~DRVDRV & ~CAN_BT} for clarity
+ 03D9 B700       900          sta PORTA       ; don't feed CAN_BT to pull downs
+                 901  * now make sure power down state is valid!
+ 03DB A6F3       902          lda #{DRVLMPS | DRVDRV | CAN_BT}
+ 03DD B704       903          sta DDRA        ; interrupts only from NGN_SW, BRK_SW, EMG_BT
+ 03DF B710       904          sta PDRA        ; pull downs only on inputs
+ 03E1 3F01       905          clr PORTB       ; initial outputs (do port B just in case)
+ 03E3 3F05       906          clr DDRB        ; B initially input
+ 03E5 3F11       907          clr PDRB        ; with pull downs set
+                 908  * make sure EPROM programming stuff is out of the way
+                 909  *        clr EPROG       ; ICS complains, skip by hand
+ 03E7 3F0F       910          clr PESCR
+                 911  * enable external interrupts
+ 03E9 1E0A       912          bset IRQE_,ISCR ; DO NOT clear the flag (don't miss anything)
+ 03EB 8E         913          stop    ; also shuts timer down
+ 03EC 83         914          swi     ; should never come here (IRQSRV resests stack pointer)
+ 03ED 83         915          swi     ; more unused ROM
+ 03EE 83         916          swi
+ 03EF 83         917          swi
+                 918  
+ 03F0            919          SUBHEADER 'Interrupt Vectors'
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 23
+Turn Signal Switch by Joel Matthew Rees
+Interrupt Vectors
+
+ 03F0            919          PAGE
+                 920  
+ 03F8            921          org VECTORS
+ 03F8 0203       922          fdb TIMSRV
+ 03FA 0355       923          fdb IRQSRV
+ 03FC 0355       924          fdb SWISRV
+ 03FE 035D       925          fdb RSTSRV
+                 926  
+ 0400            927          SUBHEADER 'Symbol Table'
+ 0400            928          end
+                 929  
+                 930  
+
+ Symbol Table 
+
+ANYLITE          002B
+B0               0001
+B0_              0000
+B1               0002
+B1_              0001
+B2               0004
+B2_              0002
+B3               0008
+B3_              0003
+B4               0010
+B4_              0004
+B5               0020
+B5_              0005
+B6               0040
+B6_              0006
+B7               0080
+B7_              0007
+BRK_SW           0008
+BRK_SW_          0003
+CAN_BT           0001
+CAN_BT_          0000
+COPEN            0001
+COPR             03F0
+DBGCT            00F2
+DDRA             0004
+DDRB             0005
+DEBO             00E0
+DOSTATES         03A4
+DRVDRV           0002
+DRVDRV_          0001
+DRVLMPS          00F0
+ELAT             0004
+ELAT_            0002
+EMG_BTF          0002
+EMG_BTF_         0001
+EPGM             0001
+EPGM_            0000
+EPROG            0018
+FLASH            00E9
+FLASH0           0001
+FLASH1           0001
+FLDARK           00EA
+FLMASK           00EB
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 24
+Turn Signal Switch by Joel Matthew Rees
+Symbol Table
+
+FRNTDRV          00C0
+F_BRK            0020
+F_BRK_           0005
+F_CAN            0004
+F_CAN_           0002
+F_EMG            0008
+F_EMG_           0003
+F_LDRV           0080
+F_LDRV_          0007
+F_LFT            0002
+F_LFT_           0001
+F_MNC            0080
+F_NGN            0010
+F_NGN_           0004
+F_OPC            0040
+F_RDRV           0040
+F_RDRV_          0006
+F_RGT            0001
+F_RGT_           0000
+IRQE             0080
+IRQE_            0007
+IRQF             0008
+IRQF_            0003
+IRQR             0002
+IRQR_            0001
+IRQSRV           0355
+IRQVEC           03FA
+ISCR             000A
+ISTATE           00E5
+LASTST           00ED
+LEVEL            0002
+LFTDRV           00A0
+LFT_BT           0002
+LFT_BT_          0001
+LVRE             0008
+MOR              0017
+MPGM             0002
+MPGM_            0001
+NGN_SW           0004
+NGN_SW_          0002
+NGN_TIM          00E7
+PDRA             0010
+PDRB             0011
+PEBSR            000E
+PEDATA           0080
+PEDATA_          0007
+PEPGM            0020
+PEPGM_           0005
+PEPRZF           0001
+PEPRZF_          0000
+PESCR            000F
+PIN3             0040
+PIRQ             0004
+PORTA            0000
+PORTB            0001
+RAMBEG           00E0
+RAMSIZ           0020
+RC               0020
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 25
+Turn Signal Switch by Joel Matthew Rees
+Symbol Table
+
+REARDRV          0030
+RESET            03FE
+RGTDRV           0050
+RGT_BT           0001
+RGT_BT_          0000
+ROMBEG           0200
+RSTSRV           035D
+RT0              0001
+RT0_             0000
+RT1              0002
+RT1_             0001
+RTIE             0010
+RTIE_            0004
+RTIF             0040
+RTIFR            0004
+RTIFR_           0002
+RTIF_            0006
+RTIPOW           0000
+RTIRATE          0002
+R_LDRV           0020
+R_LDRV_          0005
+R_RDRV           0010
+R_RDRV_          0004
+SSTBLE           00E3
+STATES           00E6
+STKTOP           00FF
+STT0BRK          03C2
+STT0EMG          03B1
+STT0FLH          03CC
+STT0LFT          03B6
+STT0RGT          03BB
+STTBRK           03BD
+SWAIT            0010
+SWISRV           0355
+SWIVEC           03FC
+SWPDI            0080
+TCNTR            0009
+TIMDUN           033D
+TIMDUX           034B
+TIMER            0009
+TIMOUT           0001
+TIMSRV           0203
+TIMVEC           03F8
+TM0TURN          024C
+TMCAN0           02CD
+TMCLOCK          02E5
+TMF0BRK          0285
+TMF0EMG          028E
+TMF1CAN          0276
+TMFLASH          0329
+TMFLH0           033D
+TMFLTM           033B
+TMFNGN0          02E5
+TMIEMG           0219
+TMMFLH           0307
+TMMFLH0          030D
+TMNGNR0          0329
+TMORST           02F3
+
+
+TURNSIG.asm            Assembled with IASM   11/19/1993  00:26  PAGE 26
+Turn Signal Switch by Joel Matthew Rees
+Symbol Table
+
+TMPTRN           00EC
+TMSCLK           030D
+TMSTRN           02AA
+TMTBIT6          0235
+TMTBIT7          023B
+TMTNTN           0246
+TOF              0080
+TOFR             0008
+TOFR_            0003
+TOF_             0007
+TOGGLE           00E4
+TOIE             0020
+TOIE_            0005
+TSCR             0008
+TSTROM           03F0
+TURNSIG          0003
+TURNSTATE        0295
+VECTORS          03F8
+XTAL             0001

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