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;
; $Id: test_stack.asm,v 1.3 2001/10/15 18:52:00 troth Exp $
;
; Test pushing 4 bytes onto the stack. When done, expect to see:
;; last 4 bytes of sram with 00, 01, 02, 03
;; SPH, SPL with 0x02, 0x5b
;; SREG -> 0x02
;.device AT90S8515
.include "8515def.inc"
rjmp MAIN ; reset
nop ; int0
nop ; int1
nop ; timer1 capt
nop ; timer1 compa
nop ; timer1 compb
nop ; timer1 ovf
nop ; timer0 ovf
nop ; spi, stc
nop ; uart, rx
nop ; uart, udre
nop ; uart, tx
nop ; ana_comp
MAIN:
;; init stack pointer to 0x025f (the last byte of int sram)
ldi r16, lo8(RAMEND); low byte of end of int sram
out SPL, r16
ldi r16, hi8(RAMEND); high byte of end of int sram
out SPH, r16
;; push 4 numbers onto the stack (use r16 as a counter)
ldi r16, 0x03
PUSH_EM:
push r16 ; push r16 onto the stack, should inc SP
cpi r16, 0x00 ; compare r16 with $00, should set sreg
breq PUSHED_ALL ; branch to end if sreg['Z'] == 1
dec r16 ; decrment r16
rjmp PUSH_EM ; repeat
PUSHED_ALL:
nop
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