FMUL:
MOV A,R3
ORL A,R4
JZ MUL6
MOV A,R6
ORL A,R7
JZ MUL5
MOV A,R7
MOV B,R4
MUL AB
MOV A,B
XCH A,R7
MOV B,R3
MUL AB
ADD A,R7
MOV R7,A
CLR A
ADDC A,B
XCH A,R4
MOV B,R6
MUL AB
ADD A,R7
MOV R7,A
MOV A,B
ADDC A,R4
MOV R4,A
CLR A
RLC A
XCH A,R3
MOV B,R6
MUL AB
ADD A,R4
MOV R4,A
MOV A,B
ADDC A,R3
MOV R3,A
JB ACC.7,MUL2
MOV A,R7
RLC A
MOV R7,A
LCALL RL1
MUL2:
MOV A,R7
JNB ACC.7,MUL3
INC R4
MOV A,R4
JNZ MUL3
INC R3
MOV A,R3
JNZ MUL3
MOV R3,#80H
INC R2
MUL3:
MOV A,R2
ADD A,R5
MD:
MOV R2,A
JB ACC.7,MUL4
JNB ACC.6,MUL6
MOV R2,#3FH
SETB OV
RET
MUL4:
JB ACC.6,MUL6
MUL5:
CLR A
MOV R3,A
MOV R4,A
MOV R2,#41H
MUL6:
CLR OV
RET
