確定一下 SPI Mode 有正確設定嗎?
參考一下 Microchip 所提供的範例程式: AN1018

http://www.microchip.com/stellent/idc ... eId=1824&appnote=en025489

小弟使用C18 用到SPI部分與25LC160 傳輸讀取資料
程式會卡在busy_polling();
就算去掉 讀到的值 也是錯誤
石英晶體是接16M
用的實驗版是APP001
請問是什麼原因呢!? 謝謝
以下是程式碼

#include <p18cxxx.h>
#include <spi.h>
// FUNCTION Prototypes
void set_wren(void);
void busy_polling(void);
void status_write(unsigned char data);
void byte_write(unsigned char addhigh,unsigned char addlow,unsigned char data);
unsigned char byte_read (unsigned char addhigh,unsigned char addlow);

unsigned char var;
unsigned char ff=0x00;

#define SPI_CS LATAbits.LATA5
//**************************************************
void main(void)
{
ADCON1=0X0F;
TRISA = 0;
SPI_CS = 1; // ensure SPI memory device
// Chip Select is reset
OpenSPI(SPI_FOSC_16, MODE_00, SMPEND);
set_wren();
status_write(0);
busy_polling();
set_wren();
byte_write(0x00, 0x61, 'E');
busy_polling();
ff = byte_read(0x00, 0x61);
CloseSPI();
while(1);
}
void set_wren(void)
{
SPI_CS = 0; //assert chip select
var = putcSPI(SPI_WREN); //send write enable command
SPI_CS = 1; //negate chip select
}
void byte_write (unsigned char addhigh,unsigned char addlow,unsigned char data)
{
SPI_CS = 0; //assert chip select
var = putcSPI(SPI_WRITE); //send write command
var = putcSPI(addhigh); //send high byte of address
var = putcSPI(addlow); //send low byte of address
var = putcSPI(data); //send data byte
SPI_CS = 1; //negate chip select
}
unsigned char byte_read (unsigned char addhigh,unsigned char addlow)
{
SPI_CS = 0; //assert chip select
var = putcSPI(SPI_READ); //send read command
var = putcSPI(addhigh); //send high byte of address
var = putcSPI(addlow); //send low byte of address
var = getcSPI(); //read single byte
SPI_CS = 1;
return (var);
}
void status_write (unsigned char data)
{
SPI_CS = 0;
var = putcSPI(SPI_WRSR); //write status command
var = putcSPI(data); //status byte to write
SPI_CS = 1; //negate chip select
}
void busy_polling (void)
{
do
{
SPI_CS = 0; //assert chip select
var = putcSPI(SPI_RDSR); //send read status command
var = getcSPI(); //read data byte
SPI_CS = 1; //negate chip select
} while (var & 0x01); //stay in loop until !busy
}