;-------------------------------------
;  HC908 Example #1
;-------------------------------------

;filename: example1.asm
;written by Kenrick Chin
;2003.12.04 - first writing

;This example is used to test the operation
;of the assembler and download process.
;Assembled code is placed in SRAM
;and then executed directly from SRAM
;No flash locations are used.

;An external oscillator at 9.8304MHz is assumed.

;Both PORTA and PORTB output pins are used.

;The output pulse on any output pin is high for 6 cycles
;and low for 9 cycles.
;Hence the total waveform is 2.44us(H) + 3.66us(L) = 6.10us

;-------------------------------------
;  MCU Definitions
;-------------------------------------

SRAM   EQU  $80

PORTA  EQU  $00
PORTB  EQU  $01
DDRA   EQU  $04
DDRB   EQU  $05

INTSCR  EQU $1D
CONFIG2 EQU $1E
CONFIG1 EQU $1F
OSCTRIM EQU $38

COPD   EQU  0
RSTEN  EQU  0

;-------------------------------------
;  Start of Bootstrap
;-------------------------------------

       ORG  SRAM

boot   BOOT

        BSET  COPD CONFIG1    ;turn off watchdog
        BSET  RSTEN CONFIG2   ;enable RESET pin

;initialize ports
	 LDA    #$FF
       STA    DDRA
       STA    DDRB

main   STA    PORTA
       STA    PORTB
       CLR    PORTA
       CLR    PORTB
       BRA   main

       ENDB boot

       END

;-------------------------------------
;  End of Example #1
;-------------------------------------