SPI演示的STC-MCU版本

/*------------------------------------------------------------------*/ /* --- STC MCU International Limited -------------------------------*/ /* --- STC 1T Series MCU SPI Demo(1 master and 1 slave) ------------*/ /* --- Mobile: (86)13922805190 -------------------------------------*/ /* --- Fax: 86-755-82944243 ----------------------------------------*/ /* --- Tel: 86-755-82948412 ----------------------------------------*/ /* --- Web: www.STCMCU.com -----------------------------------------*/ /* If you want to use the program or the program referenced in the */ /* article, please specify in which data and procedures from STC */ /*------------------------------------------------------------------*/ #include "reg51.h" //#define MASTER //define:master undefine:slave #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 = 0xcd; //SPI status register #define SPIF 0x80 //SPSTAT.7 #define WCOL 0x40 //SPSTAT.6 sfr SPCTL = 0xce; //SPI control register #define SSIG 0x80 //SPCTL.7 #define SPEN 0x40 //SPCTL.6 #define DORD 0x20 //SPCTL.5 #define MSTR 0x10 //SPCTL.4 #define CPOL 0x08 //SPCTL.3 #define CPHA 0x04 //SPCTL.2 #define SPDHH 0x00 //CPU_CLK/4 #define SPDH 0x01 //CPU_CLK/16 #define SPDL 0x02 //CPU_CLK/64 #define SPDLL 0x03 //CPU_CLK/128 sfr SPDAT = 0xcf; //SPI data register sbit SPISS = P1^3; //SPI slave select, connect to slave' SS(P1.4) 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 and slave /////////////////////////////////////////////////////////// void main() { InitUart(); //initial UART InitSPI(); //initial SPI while (1) { #ifdef MASTER //for master (receive UART data from PC and send it to slave, in the meantime // receive SPI data from slave and send it to PC) SendUart(SPISwap(RecvUart())); #else //for salve (receive SPI data from master and ACC = SPISwap(ACC); // send previous SPI data to master) #endif } } /////////////////////////////////////////////////////////// void InitUart() { SCON = 0x5a; //set UART mode as 8-bit variable baudrate TMOD = 0x20; //timer1 as 8-bit auto reload mode AUXR = 0x40; //timer1 work at 1T mode TH1 = TL1 = BAUD; //115200 bps TR1 = 1; } /////////////////////////////////////////////////////////// void InitSPI() { SPDAT = 0; //initial SPI data SPSTAT = SPIF | WCOL; //clear SPI status #ifdef MASTER SPCTL = SPEN | MSTR; //master mode #else SPCTL = SPEN; //slave mode #endif } /////////////////////////////////////////////////////////// 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) { #ifdef MASTER SPISS = 0; //pull low slave SS #endif SPDAT = dat; //trigger SPI send while (!(SPSTAT & SPIF)); //wait send complete SPSTAT = SPIF | WCOL; //clear SPI status #ifdef MASTER SPISS = 1; //push high slave SS #endif return SPDAT; //return received SPI data }