STC15与MAX31856的SPI读取全是0xFF -

//本示例在Keil开发环境下请选择Intel的8058芯片型号进行编译
//若无特别说明,工作频率一般为11.0592MHz
#include "reg51.h"
#include<stdio.h>
#include<intrins.h>
#define FOSC 11059200UL
#define BAUD 115200
typedef unsigned char BYTE;
typedef unsigned int WORD;
typedef unsigned char u8;
typedef unsigned int u16;
#define SR_Read 0x0F
#define URMD 0 //0:使用定时器2作为波特率发生器
//1:使用定时器1的模式0(16位自动重载模式)作为波特率发生器
//2:使用定时器1的模式2(8位自动重载模式)作为波特率发生器
sfr P1M1 = 0x91; //PxM1.n,PxM0.n =00--->Standard, 01--->push-pull
sfr P1M0 = 0x92; // =10--->pure input, 11--->open drain
sfr P0M1 = 0x93;
sfr P0M0 = 0x94;
sfr P2M1 = 0x95;
sfr P2M0 = 0x96;
sfr P3M1 = 0xB1;
sfr P3M0 = 0xB2;
sfr P4M1 = 0xB3;
sfr P4M0 = 0xB4;
sfr P5M1 = 0xC9;
sfr P5M0 = 0xCA;
sfr P6M1 = 0xCB;
sfr P6M0 = 0xCC;
sfr P7M1 = 0xE1;
sfr P7M0 = 0xE2;
sfr T2H = 0xd6; //定时器2高8位
sfr T2L = 0xd7; //定时器2低8位
sfr AUXR = 0x8e; //辅助寄存器
sfr P_SW1 = 0xa2; //外设功能切换寄存器1
#define SPI_S0 0x04 //P_SW1.2
#define SPI_S1 0x08 //P_SW1.3
sfr SPSTAT = 0xcd; //SPI状态寄存器
#define SPIF 0x80 //SPSTAT.7
#define WCOL 0x40 //SPSTAT.6
sfr SPCTL = 0xce; //SPI控制寄存器
#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数据寄存器
sbit SPISS = P2 ^ 4; //SPI从机选择口, 连接到其它MCU的SS口
//当SPI为一主多从模式时,请使用主机的普通IO口连接到从机的SS口
sfr IE2 = 0xAF; //中断控制寄存器2
#define ESPI 0x02 //IE2.1
void InitUart();
void InitSPI();
u16 WenDu;
u8 WenDu_Time, Error;
BYTE SPISwap(BYTE dat);
u8 SPI_RW_Reg(u8 reg, u8 value);
///////////////////////////////////////////////////////////
void Delay500ms(void) //@11.0592MHz
{
unsigned char data i, j, k;
_nop_();
_nop_();
i = 22;
j = 3;
k = 227;
do
{
do
{
while (--k);
}
while (--j);
}
while (--i);
}
void main()
{
u16 x, y;
P0M0 = 0x00;
P0M1 = 0x00;
P1M0 = 0x00;
P1M1 = 0x00;
P2M0 = 0x00;
P2M1 = 0x00;
P3M0 = 0x00;
P3M1 = 0x00;
P4M0 = 0x00;
P4M1 = 0x00;
P5M0 = 0x00;
P5M1 = 0x00;
P6M0 = 0x00;
P6M1 = 0x00;
P7M0 = 0x00;
P7M1 = 0x00;
InitUart(); //初始化串口
InitSPI(); //初始化SPI
IE2 |= ESPI;
EA = 1;
while (1)
{
Delay500ms() ;
x = SPISwap(0x00);//00~0F 都是只读配置reg
y = SPISwap(0x01);
printf("MAX31856_Read00:%d ;Read01:%d\n", x, y);
}
}
BYTE SPISwap(BYTE dat)
{
SPDAT = dat; //触发SPI发送数据
while (!(SPSTAT & SPIF)); //等待发送完成
SPSTAT = SPIF | WCOL; //清除SPI状态位
return SPDAT; //返回SPI数据
}
//SPI写寄存器
//reg:指定寄存器地址
//value:写入的值
u8 SPI_RW_Reg(u8 reg, u8 value)
{
u8 status;
status = SPISwap(reg); //返回从MISO读出的数据,status应为上次向该寄存器内写的value
SPISwap(value); //写入寄存器的值
return status; // 返回状态值
}
///////////////////////////////////////////////////////////
void InitUart()
{
SCON = 0x5a; //设置串口为8位可变波特率
#if URMD == 0
T2L = (65536 - (FOSC / 4 / BAUD));
T2H = (65536 - (FOSC / 4 / BAUD)) >> 8;
AUXR = 0x14; //T2为1T模式, 并启动定时器2
AUXR |= 0x01; //选择定时器2为串口1的波特率发生器
#elif URMD == 1
AUXR = 0x40; //定时器1为1T模式
TMOD = 0x00; //定时器1为模式0(16位自动重载)
TL1 = (65536 - (FOSC / 4 / BAUD));
TH1 = (65536 - (FOSC / 4 / BAUD)) >> 8;
TR1 = 1; //定时器1开始启动
#else
TMOD = 0x20; //设置定时器1为8位自动重装载模式
AUXR = 0x40; //定时器1为1T模式
TH1 = TL1 = (256 - (FOSC / 32 / BAUD));
TR1 = 1;
#endif
}
///////////////////////////////////////////////////////////
void InitSPI()
{
ACC = P_SW1; //可用于测试U7,U7使用的是第二组SPI控制Flash
ACC &= ~(SPI_S0 | SPI_S1); //SPI_S0=1 SPI_S1=0
ACC |= SPI_S0; //(<b>P2.4///SPISS, P2.3/MOSI_2, P2.2/MISO_2, P2.1/SCLK_2</b>)
P_SW1 = ACC;
SPDAT = 0; //初始化SPI数据
SPSTAT = SPIF | WCOL; //清除SPI状态
SPCTL = SPEN | MSTR; //设置SPI为主模式
//SPCTL = SPEN | MSTR | SSIG | SPDLL; //主机模式忽略SS引脚
}

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