Control Stepper Motor Steering

Single turn

Code segement
Assume Cs:code,ds:code
Org 100h
START:JMP begin
Psta db 05h,15h,14h,54h,50h,51h,41h,45h; phase sequence table
Message db ' press SW2 to start! ' ; System hints
DB 0dh,0ah
DB ' If you want to quit,press SW1! '
DB 0dh,0ah, ' $ '
Begin:mov Ax,cs
MOV Ds,ax
mov ah,09h; display prompt information
MOV dx,seg message
int 21h
MOV dx,303h; initialize 8255A
MOV a1,81h
Out Dx,al
mov al,09h; pc4=1, off 74LS37
Out Dx,al
L:mov dx,302h; check SW2 press? (pc1=0?) ）
In AL,DX
and al,02h; not pressed, waiting
JNZ L
mov dx,303h; pc4=0, open 74ls37
MOV al,08h
Out Dx,al
Reload:mov Si,sffset Psta; Set the phase order table pointer
MOV cx,8; set 8 beats cycle times
Lop:mov dx,302h; check SW1 press? (pc0=0?) ）
In AL,DX
and al,01h
JZ quit; pressed, exited
MOV al,[si]; not pressed, send phase order form code to PA
MOV dx,300h
Out Dx,al
MOV di,0afh
MOV BX,0FFFFH; delay
Delay:dec BX
JNZ delay
Dec di
JNZ delay
Inc si; Phase sequence table pointer +1
Dec CX; Number of cycles-1
JNZ Lop; less than 8 times, continue
JMP Reload; 8 times, re-
Quit:mov dx,303h; pc4=1
MOV al,09
Out Dx,al
MOV ah,4ch; program exit
int 21h
Code ends
End Start

Positive and negative turn

Code segment

Assume Cs:code,ds:code
Org 100h
START:JMP begin
Psta DB 05h,15h,14h,54h,50h,51h,41h,45h
PSTB db 45h,41h,51h,50h,54h,14h,15h,05h; phase sequence table
Message db ' press SW2 to start! ' ; System hints
DB 0dh,0ah
DB ' If you want to quit,press SW1! '
DB 0dh,0ah, ' $ '
Begin:mov Ax,cs
MOV Ds,ax
mov ah,09h; display prompt information
MOV dx,seg message
MOV ds,dx
MOV Dx,offset message
int 21h
MOV dx,303h; initialize 8255A
MOV al,81h
Out Dx,al
mov al,09h; pc4=1, off 74LS37
Out Dx,al
L:mov dx,302h; check SW2 press? (pc1=0?) ）
In AL,DX
and al,02h; not pressed, waiting
JNZ L
mov dx,303h; pc4=0, open 74ls37
MOV al,08h
Out Dx,al
Reload:mov Si,offset Psta
MOV cx,8; set 8 beats cycle times
Lop1:mov dx,302h; check SW1 press? (pc0=0?) ）
In AL,DX
and al,01h
JZ lop2; pressed, exited
MOV al,[si]; not pressed, send phase order form code to PA
MOV dx,300h
Out Dx,al
MOV di,0afh
MOV BX,0FFFFH; delay
Delay1:dec BX
JNZ delay1
Dec di
JNZ delay1
Inc si; Phase sequence table pointer +1
Dec CX; Number of cycles-1
JNZ Lop1; Less than 8 times, continue
JMP Reload; 8 times, re-
Reload1:mov Si,offset Pstb
MOV cx,8; set 8 beats cycle times
Lop2:mov dx,302h; check SW1 press? (pc0=0?) ）
In AL,DX
and al,02h
JZ lop1; pressed, exited
MOV al,[si]; not pressed, send phase order form code to PA
MOV dx,300h
Out Dx,al
MOV di,0afh
MOV BX,0FFFFH; delay
Delay:dec BX
JNZ delay
Dec di
JNZ delay
Inc si; Phase sequence table pointer +1
Dec CX; Number of cycles-1
JNZ lop2; Less than 8 times, continue
JMP Reload1; 8 times, re-

Code ends
End Start

Control Stepper Motor Steering