Keil forum about if (a<= x) asm code

This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

about if (a<= x) asm code

M8051Ask over 6 years ago

Hi All

In Keil C51 version 4

if (a<= 240) will get follow asm code

MOV A,R7
SETB C
SUBB A,#0F0H

JNC ?C0001

In Keil C51 Version 5 will get follow asm code

MOV A,R7
SETB C
SUBB A,#0F0H
MOV A,#080H
SUBB A,#080H
JNC ?C0001

Why add those two line asm code??

MOV A,#080H
SUBB A,#080H

Sorry , my poor english ^^"""

Thanks a lot

FYR