#define FOSC 18432000L
#define BAUD (256 - FOSC / 32 / 115200)
typedef unsigned char BYTE;
typedef unsigned int WORD;
typedef unsigned long DWORD;
sfr AUXR = 0x8e; //Auxiliary register
sfr SPSTAT = 0x84; //SPI status register
#define SPIF 0x80 //SPSTAT.7
#define WCOL 0x40 //SPSTAT.6
sfr SPCTL = 0x85; //SPI control register
#define SSIG 0x80 //SPCTL.7
#define SPEN 0x40 //SPCTL.6
#define DORD 0x20 //SPCTL.5
#define MSTR 0x 0 //SPCTL.4
#define CPOL 0x08 //SPCTL.3
#define CPHA 0x04 //SPCTL.2
#define SPDHH 0x00 //CPU_CLK/4
#define SPDH 0x01 //CPU_CLK/ 6
#define SPDL 0x02 //CPU_CLK/
#define SPDLL 0x03 //CPU_CLK/ 28
sfr SPDAT = 0x86; //SPI data register
sbit SPISS = P1^3; //SPI slave select, connect to slave' SS(P .4) pin
void InitUart();
void InitSPI();
void SendUart(BYTE dat); //send data to PC
BYTE RecvUart(); //receive data from PC
BYTE SPISwap(BYTE dat); //swap SPI data between master
///////////////////////////////////////////////////////////
void main()
{
InitUart(); //initial UART
InitSPI(); //initial SPI
while (1 )
{
if (RI)
{
SPCTL = SPEN | MSTR; //set as master
SendUart(SPISwap(RecvUart()));
SPCTL = SPEN; //reset as slave
}
if (SPSTAT & SPIF)
{
SPSTAT = SPIF | WCOL; //clear SPI status
SPDAT = SPDAT; //mov data from receive buffer to send buffer
}
}
}
///////////////////////////////////////////////////////////
void InitUart()
{
SCON = 0x5a; //set UART mode as 8-bit variable baudrate
TMOD = 0x20; //timer as 8-bit auto reload mode
AUXR = 0x40; //timer work at T mode
TH1 = TL1 = BAUD; // 5200 bps
TR1 =1 ;
}
///////////////////////////////////////////////////////////
void InitSPI()
{
SPDAT = 0; //initial SPI data
SPSTAT = SPIF | WCOL; //clear SPI status
SPCTL = SPEN; //slave mode
}
///////////////////////////////////////////////////////////
void SendUart(BYTE dat)
{
while (!TI); //wait pre-data sent
TI = 0; //clear TI flag
SBUF = dat; //send current data
}
///////////////////////////////////////////////////////////
BYTE RecvUart()
{
while (!RI); //wait receive complete
RI = 0; //clear RI flag
return SBUF; //return receive data
}
/////////////////
//////////////////////////////////////////
BYTE SPISwap(BYTE dat)
{
SPISS = 0; //pull low slave SS
SPDAT = dat; //trigger SPI send
while (!(SPSTAT & SPIF)); //wait send complete
SPSTAT = SPIF | WCOL; //clear SPI status
SPISS =1 ; //push high slave SS
return SPDAT; //return received SPI data
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