stepn.asm

给出具体的几个汇编源代码.相信您看过之后对汇编语言编程会有所了解.

; ***************************************************************************
; File: STEPN.ASM -> First Application program for the 'C54x DSKplus
;
; ***************************************************************************

         .width   80
         .length  55
         .title "STEPN.ASM program"
         .mmregs
         .setsect ".text",   0x300,0
         .setsect ".data", 0x0500, 1    ; defines the absolute addrs

        .text
start:
        DP=#004H    ; DP=0000 0010 0 Smem=0000 0010 0xxx xxxx=02XX
        SP=#0FFAH   
        ar5=#0205h  
        ar2=#0202h  
        AR4=#0204H  
        ar3=#203h   
        *ar2=#00h   
        bk=#04h     
        ar3=#stepm  

; d7,d6, d5, d4, d3 ,d2,d1,d0  =port(00)
; md,stp,f/r,sped.....speed..
wait
        *ar5=port(00) 
        tc=bit(*ar5,15-1) 
        if (tc) goto wait

        tc=bit(*ar5,15-0) 
        if (tc) goto cntmd1 

ntcmd0
        b=*ar5         
        b = b & #00F8h
        *ar4=b<<7    
        tc=bit(*ar5,15-2) 
        if (tc) goto srevs 

sforwp
        NOP
        PORT(01)=*ar3+% 
        call   tdelay  
        NOP
OUTP2
        NOP        
        goto wait  
        NOP
        NOP
srevs
        PORT(01)=*ar3-% 
        call   tdelay 
        NOP
        NOP
OUTP3:
        NOP          
        goto wait  
        nop
        nop


cntmd1:
        ar6 = #cntd 

nexte:  NOP
        b=*ar6+ 
        B= B & #0F000H
        B= B << -12   
        if (BEQ) goto shalt 
        b=b-#01            
        if (BEQ) goto sforw
        b=b-#01            
        if (BEQ) goto srevw
        b=b-#01            
        if (BEQ) goto wait 
        NOP
        NOP

sforw:  NOP
        b=*ar6- 
                
        brc =b 
        blockrepeat(stepf) 
        b=*ar6  
        b= b & #0fffh
        *ar4=b<<4 
        PORT(01)= *ar3+% 
        call   tdelay 
        NOP
        nop
stepf:
        nop
        mar(*ar6+) 
        goto nexte 
        NOP
        NOP

srevw:  NOP
        b=*ar6- 
        brc =b  
        blockrepeat(stepr) 
        b=*ar6  
        b= b & #0fffh
        *ar4=b<<4 
        PORT(01)=*ar3-%  
        call   tdelay   
        nop
        NOP
stepr:
        nop
        mar(*ar6+) 
        goto nexte 
        NOP
        NOP

shalt:   NOP
        b=*ar6-  
        brc =b   
        blockrepeat(steph) 
        b=*ar6   
        b= b & #0fffh
        *ar4=b<<4 
        nop
        NOP
        call   tdelay 
        nop
steph:  NOP
        nop
        mar(*ar6+) 
        goto nexte 
        NOP
        NOP

tdelay:
DLT2:   NOP
        CALL DLYT   
        A=*AR4      
        A= A-#1     
        *AR4=A      
        IF(ANEQ) GOTO DLT2  
        RETURN     


DLYT:   AR7=#0100H  
        AR0=#0000H  
DLT1:
        MAR(*AR7-) 
        NOP        
        NOP        
        TC = (AR0 == AR7) 
        IF(NTC) GOTO DLT1  
        NOP       
        RETURN     


        .data
stepm:
       .word 000cch     ;    4
       .word 00066h     ;    5
       .word 00033h     ;    6
       .word 00099h     ;    7


;0=halt 1=forw 2=revw 3=restart
cntd:
       .word 01080h     ;    forw sped=080h
       .word 00100h     ;    step 0010h
       .word 00020h     ;    halt sped 010h=unit time=ut
       .word 00010h     ;    step=0010h=0010h)ut

       .word 02060h     ;    revw sped=060h
       .word 00140h     ;    step 0010h
       .word 00080h     ;    halt sped 080h=unit time=ut
       .word 00010h     ;    step=0010h=0010h)ut=0010h*80h

       .word 01130h     ;    forw sped=130h
       .word 00040h     ;    step 040h
       .word 01010h     ;    forw sped520h
       .word 800       ;    step=0010h=0010h)ut

       .word 00080h     ;    halt sped=080h
       .word 00020h     ;    step 0020h
       .word 02120h     ;    revw sped120h
       .word 00040h     ;    step=0010h=0010h)ut

       .word 02010h     ;    revw sped=010h
       .word 1200       ;    step 1200
       .word 03000h     ;    restart
       .word 00000h     ;    step=0010h=0010h)ut

        .end