hi all,

i'm using the Atmel 89S8253 chip to do my project.

so it is base on the 8051.

i need to receive signal from PC in serial port to the chip.

my PC serial port baud rate set to 19200.

i connect the PC serial to a MAX232 chip ,then pass to the 89S8253 chip .


this is the code for reading the serial signal

JNB RI,$
MOV A,SBUF

but how can i compare the data signal received?

my objective is to receive 1 signal from PC,
then 89S8253 chip compare which signal is received and on the specify pin.

case 1
send "1" from PC to the chip,
then the 89S8253 chip will turn on port0 pin 0

case 2
send "2" from PC to the chip,
then the 89S8253 chip will turn on port0 pin 1

case 3
send "3" from PC to the chip,
then the 89S8253 chip will turn on port0 pin 2

case 4
send "4" from PC to the chip,
then the 89S8253 chip will turn on port0 pin 3


thanks for helping me!