test/test_cntr.asm

   1 ;
   2 ; $Id: test_cntr.asm,v 1.1 2004/03/20 23:05:26 titzer Exp $
   3 ;
   4 ; Use simple opcodes to test the instruction decoder.
   5 ;
   6 ;;; .device         AT90S8515
   7
   8 .include        "8515def.inc"
   9
  10 ;;; .cseg
  11         rjmp    MAIN            ; reset
  12         nop                     ; int0
  13         nop                     ; int1
  14         nop                     ; timer1 capt
  15         nop                     ; timer1 compa
  16         nop                     ; timer1 compb
  17         nop                     ; timer1 ovf
  18         nop                     ; timer0 ovf
  19         nop                     ; spi, stc
  20         nop                     ; uart, rx
  21         nop                     ; uart, udre
  22         nop                     ; uart, tx
  23         nop                     ; ana_comp
  24
  25 MAIN:
  26         ;; init stack pointer to 0x025f (the last byte of int sram)
  27                 ldi             r16, 0x5f               ; low byte of end of int sram
  28                 out             SPL, r16
  29                 ldi             r16, 0x02               ; high byte of end of int sram
  30                 out             SPH, r16
  31
  32                 ldi             r16, 0xff               ; initialize outer loop counter
  33
  34 LOOP1:
  35                 cpi             r16, 0x00
  36                 breq    DONE
  37                 dec             r16
  38                 rcall   INNER
  39                 rjmp    LOOP1
  40
  41 INNER:
  42                 ldi             r17, 0xff               ; initialize inner loop counter
  43
  44 LOOP2:
  45                 cpi             r17, 0x00
  46                 breq    REPEAT
  47                 dec             r17
  48                 rjmp    LOOP2
  49 REPEAT:
  50                 ret
  51
  52 DONE:
  53                 nop