Julius:

The programmer working in assembler should use a standard header (include) file for the processor you are using. All assemblers I know of come with these. The advantage is that you can use P3 for the port name and avoid the kind of mistake in your program. This file may be named something like REG52.INC

BTW. The SFR address for Port 3 on a standard architecture 8051/8052 is:

; BYTE Registers
P0 DATA 80H
P1 DATA 90H
P2 DATA 0A0H
P3 DATA 0B0H
PSW DATA 0D0H

Also if you include the proper header file you can make your code way more readable if you use syntax like...


SETB P3.4

CLR P3.4


Michael Karas