/*******************************************************************************
模块名称： spi.h
模块说明： c51单片机的i/o模拟spi操作
创建时间： 2005/03/09
创建者： xichen
********************************************************************************/
#ifndef SPI_H
#define SPI_H
sbit SPIS_N = P2^1;
sbit SPIC = P2^3;
sbit SPID = P2^2;
sbit SPIQ = P2^4;
extern void spi_reset();
extern void spi_write(unsigned char spi_bValue);
extern unsigned char spi_read();
#endif
/*******************************************************************************
模块名称： spi.c
模块说明： c51单片机的i/o模拟spi操作
创建时间： 2005/03/09
创建者： xichen
********************************************************************************/
#include "includes.h"
#define set_spi_cs() SPIS_N =1
#define clr_spi_cs() SPIS_N =0
#define set_spi_clk() SPIC =1
#define clr_spi_clk() SPIC =0
#define set_spi_di() SPID =1
#define clr_spi_di() SPID =0
#define read_spi_do() SPIQ
//------------------------------------------
void spi_reset()
{
set_spi_cs();
}
//-----------------------------------------
void spi_write(unsigned char spi_bValue)
{
unsigned char no;
clr_spi_cs();
for (no=0;no<8;no++)
{
clr_spi_clk();
if ((spi_bValue &0x80)==0x80)
set_spi_di();
else
clr_spi_di();
set_spi_clk();
spi_bValue = (spi_bValue <<1);
}
}
//----------------------------------------------
unsigned char spi_read()
{
unsigned char no,spi_bValue;
clr_spi_cs();
for (no=0;no<8;no++)
{
clr_spi_clk();
spi_bValue = (spi_bValue <<1);
set_spi_clk();
if (read_spi_do() ==1)
spi_bValue |=0x01;
else
spi_bValue &=~0x01;
}
return spi_bValue;
}