Key serial port

Labels: C language single-chip microcomputer serial port

/*************************************** *****************************
Function: Send one byte of data to the serial port. The data can be displayed through a Super Terminal or serial port debugging assistant,
The baud rate of the Super Terminal is 9600 ). Every time you press the S2 key, it is released on the Super Terminal.
A string of letters "abcdefg haha" is displayed ".
Entry parameter: D: The byte data to be sent.
**************************************** ****************************/




# Include <reg52.h>
# Define jingzhen 11059200ul/* use 22.1184m crystal */
# Define botelv 9600ul/* the baud rate is 9600 */
Unsigned char zifuchuan [] = "abcdefg haha"; // the character to be displayed.
Volatile unsigned char sending;
Sbit S2 = P3 ^ 4;


Void delay (unsigned char I)
{
Unsigned char J, K;
For (j = I; j> 0; j --)
For (k = 90; k> 0; k --);
}
Void Init (void) // serial port Initialization
{
Ea = 0; // temporarily disable interruption
Tmod & = 0x0f; // timer 1 Mode Control in high 4-bit
Tmod | = 0x20; // timer 1 works in Mode 2, auto reinstallation Mode
Scon = 0x50; // Serial Port Works in Mode 1
Th1 = 256-jingzhen/(botelv * 12*16); // calculate the timer reinstallation Value
TL1 = 256-jingzhen/(botelv * 12*16 );
Pcon | = 0x80; // double the serial port baud rate
Es = 1; // The serial interrupt is allowed.
Tr1 = 1; // start timer 1
Ren = 1; // receive allowed
Ea = 1; // interrupt allowed
}


Void send (unsigned char d) // sends a byte of data. The parameter D is the data to be sent.
{
 
Sbuf = D; // write data to the serial port Buffer
Sending = 1; // set the sending flag
While (sending); // wait until the sending is completed
}


Void sendc (unsigned char * PD)
{
While (* PD )! = '\ 0') // sends a string until it reaches 0.
{
Send (* PD); // send one character
PD ++; // move to the next character
}
}


Void main ()
{
Init ();
While (1)
{
If (s2 = 0)
{
Delay (20 );
If (! S2)
{
While (! S2 );
Sendc (zifuchuan );
}
}
}
}


Void UART (void) interrupt 4 // serial port sending interruption
{
If (RI) // receives data
{
Ri = 0; // clear the interrupt request
}
Else // send one byte of data
{
Ti = 0;
Sending = 0; // clear the flag being sent
}

}