waitstates.asm

这是用VerilogHDL描述的一个8位精简指令集处理器

 ;------------------------------------
 ; Test for wait-states
 ;-------------------------------------

 org 0x0000

 ldi r0 0x04
 sta r0 0x6785 ; wait-4
 nop
 nop
 
 ldi r1 0x23
 sta r1 0x5000
 lda r0 0x5000
 cmp r1
 jmpa ne error
 ldi r1 0x56
 sta r1 0x5000
 lda r0 0x5000
 cmp r1
 jmpa ne error

 ldi r0 0x01
 sta r0 0x6785 ; wait-1 
 ldi r1 0x63
 sta r1 0x5005
 lda r0 0x5005
 cmp r1
 jmpa ne error
 ldi r1 0x66
 sta r1 0x5005
 lda r0 0x5005
 cmp r1
 jmpa ne error

 ldi r0 0x02 
 sta r0 0x6785 ; wait-2 
 ldi r1 0xa3 
 sta r1 0x5007
 lda r0 0x5007
 cmp r1
 jmpa ne error
 ldi r1 0xb7
 sta r1 0x5007
 lda r0 0x5007
 cmp r1
 jmpa ne error

 ldi r0 0x03 
 sta r0 0x6785 ; wait-3 
 ldi r1 0x87 
 sta r1 0x5002
 lda r0 0x5002
 cmp r1
 jmpa ne error
 ldi r1 0x78
 sta r1 0x5002
 lda r0 0x5002
 cmp r1
 jmpa ne error

 ldi r0 0x00 
 sta r0 0x6785 ; wait-0 
 ldi r1 0x87 
 sta r1 0x5002
 lda r0 0x5002
 cmp r1
 jmpa ne error
 ldi r1 0x78
 sta r1 0x5002
 lda r0 0x5002
 cmp r1
 jmpa ne error
 
 jmpr al finish
error:
  ldi r0 0xa2
  sta r0 0x1234
  jmpr al skip

finish:
  ldi r0 0x55
  sta r0 0xffff

skip:
  nop
  nop
  end