the function of the code “SBUF = value”.in RS232 interfacing code by som9543

[query]

In RS232 interfacing code with 8051 the receive code is given as

void recieve() //Function to receive serial data
{
unsigned char value;
while(RI==0);
SBUF=value;
P1=SBUF;
RI=0;
}

please let me know the function of the code “SBUF = value”. why it is important to assign some unknown value to SBUF?

[GANEEV SINGH]

Hi there

I guess the above code is not correct, shouldn't it be:

void recieve() //Function to receive serial data
{
unsigned char value;
while(RI==0);    //waits untill any reception occurs
value=SBUF;      //stores 1 byte data in value 
P1=vlaue;         //that value is also copied to PORT1
RI=0;               //makes RX part get ready for another reception
}

At the end of this function you could also add SBUF=0;(just after RI=0;) to ensure no garbage value stays inside SBUF register, which might have affected the upcoming reception.

[Ashutosh Bhatt]

receive function is just to receive value from serial port

so we can not assign any value to SBUF

actually it should be value = SBUF

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