stc_spi.c

用51单片机解码JPEG文件

#include "stc_new_8051.h"
#include "stc_spi.h"

void spi_init(unsigned char n) //STC 硬件SPI初始化，n为分频数，影响SPI的通信速度
{
 switch(n)
 {
  case 4:
         SPCTL=0xdc;
		 break;
  case 16:
         SPCTL=0xdd;
		 break;
  case 64:
         SPCTL=0xde;
		 break;
  case 128:
         SPCTL=0xdf;
		 break;
 }
 SPSTAT=0xc0;
}

void spi_write(unsigned char x)	//SPI 写入一个字节(STC 硬件SPI)
{
 SPDAT=x;
 while(!(SPSTAT&0x80));
 SPSTAT=0xc0;
}

/*
void spi_write(unsigned char x)	//SPI写出一个字节
{
 unsigned char i=0;
 for(i=0;i<8;i++)
 {
  TFT_SDAT=(x<<i)&0x80;
  TFT_SCLK=0;  
  TFT_SCLK=1;
 }
}
*/

unsigned char spi_read() //SPI 读取一个字节(STC 硬件SPI)
{
 SPDAT=0xff;
 while(!(SPSTAT&0x80));
 SPSTAT=0xc0;
 return SPDAT;
}