一个UART通信程序，看不太懂，求指教
#include "reg51.h"
//define baudrate const
//BAUD = 256 - SYSclk/3/BAUDRATE/M (1T:M=1; 12T:M=12)//这里的的计算公式是怎么来的
//NOTE: (SYSclk/3/BAUDRATE) must be greater than 98, (RECOMMEND GREATER THAN 11 0)
//#define BAUD 0xF400 // 1200bps @ 11 .0592MHz
//#define BAUD 0xFA00 // 2400bps @ 11 .0592MHz
//#define BAUD 0xFD00 // 4800bps @ 11 .0592MHz
//#define BAUD 0xFE80 // 9600bps @ 11 .0592MHz
//#define BAUD 0xFF40 //19200bps @ 11 .0592MHz
//#define BAUD 0xFFA0 //38400bps @ 11 .0592MHz
//#define BAUD 0xEC00 // 1200bps @ 18.432MHz
//#define BAUD 0xF600 // 2400bps @ 18.432MHz
//#define BAUD 0xFB00 // 4800bps @ 18.432MHz
//#define BAUD 0xFD80 // 9600bps @ 18.432MHz
//#define BAUD 0xFEC0 //19200bps @ 18.432MHz
#define BAUD 0xFF55 //38400bps @ 18.432MHz
//#define BAUD 0xE800 // 1200bps @ 22.11 84MHz
//#define BAUD 0xF400 // 2400bps @ 22.11 84MHz
//#define BAUD 0xFA00 // 4800bps @ 22.11 84MHz
//#define BAUD 0xFD00 // 9600bps @ 22.11 84MHz
//#define BAUD 0xFE80 //19200bps @ 22.11 84MHz
//#define BAUD 0xFF40 //38400bps @ 22.11 84MHz
//#define BAUD 0xFF80 //57600bps @ 22.11 84MHz
sfr AUXR = 0x8E;
sbit RXB = P3^0; //define UART TX/RX port
sbit TXB = P3^1;
typedef bit BOOL;
typedef unsigned char BYTE;
typedef unsigned int WORD;
BYTE TBUF,RBUF;
BYTE TDAT,RDAT;
BYTE TCNT,RCNT;//baudrate counters
BYTE TBIT,RBIT;
BOOL TING,RING;//is recive/transmit or not
BOOL TEND,REND;//mark the transmit or recive when they are complete
void UART_INIT();
BYTE t, r;
BYTE buf[16];
void main()
{
TMOD = 0x00; //timer0 in 16-bit auto reload mode
AUXR = 0x80; //timer0 working at 1T mode
TL0 = BAUD;
TH0 = BAUD>>8; //initial timer0 and set reload value
TR0 = 1; //tiemr0 start running
ET0 = 1; //enable timer0 interrupt
PT0 = 1; //improve timer0 interrupt priority
EA = 1; //open global interrupt switch
UART_INIT();
while (1)
{ //user's function
if (REND)
{
REND = 0;
buf[r++ & 0x0f] = RBUF;
}
if (TEND)
{
if (t != r)
{
TEND = 0;
TBUF = buf[t++ & 0x0f];
TING = 1;
}
}
}
}
//Timer interrupt routine for UART
void tm0() interrupt 1 using 1//中断程序的思想是什么，设计思路
{
if (RING)
{
if (--RCNT == 0)
{
RCNT = 3; //reset send baudrate counter
if (--RBIT == 0)
{
RBUF = RDAT; //save the data to RBUF
RING = 0; //stop receive
REND = 1; //set receive completed flag
}
else
{
RDAT >>= 1;
if (RXB) RDAT |= 0x80; //shift RX data to RX buffer
}
}
}
else if (!RXB)
{
RING = 1; //set start receive flag
RCNT = 4; //initial receive baudrate counter
RBIT = 9; //initial receive bit number (8 data bits + 1 stop bit)
}
if (--TCNT == 0)
{
TCNT = 3; //reset send baudrate counter
if (TING) //judge whether sending
{
if (TBIT == 0)
{
TXB = 0; //send start bit
TDAT = TBUF; //load data from TBUF to TDAT
TBIT = 9; //initial send bit number (8 data bits + 1 stop bit)
}
else
{
TDAT >>= 1; //shift data to CY
if (--TBIT == 0)
{
TXB = 1;
TING = 0; //stop send
TEND = 1; //set send completed flag
}
else
{
TXB = CY; //write CY to TX port
}
}
}
}
}
//initial UART module variable
void UART_INIT()
{
TING = 0;
RING = 0;
TEND = 1;
REND = 0;
TCNT = 0;
RCNT = 0;
}
在线求指教啊，说的明白了有更多的分相送，本人菜鸟，刚学习单片机一周多，尽量说通俗易懂点的，用的单片机stc-15f104e
[解决办法]
以前有用过51的UART通信，但是现在没用51了，这个不是很难，如果你想学话，就建议你看一本书《51单片机从零开始》，是清华出版的，讲的很详细。
[解决办法]
这程序还有注释的，不是太难，前面一段都是宏定义，后面的一些，像这样的TMOD，这应该是单片机的串口相关寄存器，通过写这些寄存器就确定了串口工作方式。另外这段代码不完整吧？程序里面是用中断方式 在进行数据接收和发送，但却只有主程序，没有中断处理。其它的就是C语言的基础了
[解决办法]
看不懂就多看几遍
[解决办法]
注释挺多的，基本都讲明白了。
看不懂可能是因为对51不熟悉
