谁帮我看看这段程序的作用
SDTZ: MOV DPTR,#BLOCKMOV A,#20
MOV 50H,A
MOVX @DPTR,A
MOV A,R4
MOV B,#4
MUL AB
MOV DPH,B
MOV DPL,A
MOV A,R3
DEC A
MOV B,#8
DIV AB
MOV A,B
MOV B,#4
MUL AB
ADD A,DPH
ADD A,#0C0H
MOV DPH,A
MOVX A,@DPTR
JNB ACC.6,SDTZ1
JB ACC.7,SDTZ2
MOV A,DPH
CLR C
SUBB A,#0C0H
MOV DPH,A
MOVX A,@DPTR
JNB ACC.0,SDTZ4
ANL A,#0FEH
MOVX @DPTR,A
MOV R5,#91H
AJMP SDTZ3
SDTZ1: MOV R5,#92H
AJMP SDTZ3
SDTZ4: MOV R5,#94H
AJMP SDTZ3
SDTZ2: MOV R5,#93H
SDTZ3: MOV DPTR,#3000H
MOVX A,@DPTR
MOV R0,A
INC DPTR
MOVX A,@DPTR
MOV DPL,A
MOV DPH,R0
MOV A,R5
MOVX @DPTR,A
INC DPTR
MOV A,R3
MOVX @DPTR,A
INC DPTR
MOV A,R4
MOVX @DPTR,A
INC DPTR
INC DPTR
MOV R0,DPH
MOV R1,DPL
MOV DPTR,#3000H
MOV A,R0
MOVX @DPTR,A
INC DPTR
MOV A,R1
MOVX @DPTR,A
RET