* filename: lab2base.asm

* System Addresses

RAM equ $0000
REG equ $1000       ;power up register base address
STACK   equ $7FFF       ;put stack at top of ram
EEPROM  equ $8000       ;for 32K EEPROM

 INCLUDE "hc11.inc"

* Operational Constants

LF  equ $A
SP  equ $20

    org RAM

* System Variables

; none

********************************** Program *******************************

    org EEPROM

start:
    sei         ;this is where the RESET vector points

*NOTE- These instructions must be executed within 64 E-cycles of reset.

    ldaa    #%0001000   ;define system options
    staa    option

    lds #STACK      ;initialize stack pointer

    ldaa    #%00000000  ;setup tmsk2
    staa    tmsk2

    ldaa    #%00000000  ;initialize pactl
    staa    pactl

    clr sccr1
    ldaa    #%00001100  ;setup serial port
    staa    sccr2

    ldaa    #%00000010  ;initialize PORTD
    staa    ddrd

    ldaa    #%00110000  ;baud=9600 w/8MHz crystal
    staa    baud

    cli         ;enable interrupts

begin
    ldaa    #LF     ;print new line
    bsr SendChar
    ldaa    #'O'        ;print "0"
    bsr SendChar
    ldaa    #'K'        ;print "K"
    bsr SendChar
    ldaa    #LF     ;print new line
    bsr SendChar

loop:
  largeNum RMW 1
  smallNum RMB 1
  ldd #$1A82
  ldaa #$1C
  std largeNum
  sta smallNum

  loop0: dec largeNum
    loop1: dec smallNum
           bne loop1
    bne loop0

  ldd #$1645
  std cleanUpMem
  loop2: dec cleanUpMem
         bne loop2
  nop

    bra loop

SendChar
    tst scsr
    bpl SendChar
    staa    scdr
    rts

    org $FFD6

* Interrupt and reset vectors.

SCI_VECT    FDB start
SPI_VECT    FDB start
PAI_VECT    FDB start
PAO_VECT    FDB start
TOF_VECT    FDB start
TOC5_VECT   FDB start
TOC4_VECT   FDB start
TOC3_VECT   FDB start
TOC2_VECT   FDB start
TOC1_VECT   FDB start
TIC3_VECT   FDB start
TIC2_VECT   FDB start
TIC1_VECT   FDB start
RTI_VECT    FDB start
IRQ_VECT    FDB start
XIRQ_VECT   FDB start
SWI_VECT    FDB start
TRAP_VECT   FDB start
COP_FAIL_VECT   FDB start
COP_CMF_VECT    FDB start
RESET_VECT  FDB start