请问单片机控制步进电机正反转以及加速减速的程序怎么写？急！！

电路图所在位置:
http://hi.baidu.com/tianhj2001/album/item/c0dc7d4fc718aed7d1c86a98.html
;文件名：DJ15-4.ASM
;程序功能：开关控制步进电机正反转

K1 EQU P3.2
K2 EQU P3.3
K3 EQU P3.4

STOP: MOV P0, #0FFH

LOOP: JNB K1, Z_M2
JNB K2, F_M2
JNB K3, STOP1
JMP LOOP
;-----------------------------
STOP1: ACALL DELAY
JNB K3, $
ACALL DELAY
JMP STOP

Z_M2: ACALL DELAY
JNB K1, $
ACALL DELAY
JMP Z_M

F_M2: ACALL DELAY
JNB K2, $
ACALL DELAY
JMP F_M

;---------------------------
Z_M: MOV R0,#00H
Z_M1: MOV A, R0
MOV DPTR, #TABLE