51 MCU simulation SPI bus communication program and proteus simulation

Share a 51 microcontroller simulation SPI bus to communicate program and simulation
schematic diagram as follows

The microcontroller source program is as follows:

#include //Header file containing microcontroller registers

#include //Header file containing _nop_() function definition

//x5045 pin definition

sbit SCK=P3^4; //Define the SCK bit as P3.4 pin

sbit SI=P3^5; //Define the SI bit as P3.5 pin

sbit SO=P3^6; //Define the SO bit as P3.6 pin

sbit CS=P3^7; //Define the SCK bit as P3.7 pin

//Function variable definition

#define WREN 0x06 //Write enable latch allows

#define WRDI 0x04 //Write enable latch disabled

#define WRSR 0x01 //Write status register

#define READ 0x03 //Read

#define WRITE 0x02 //Write

/************************************************************

Function: Delay 1ms

(3j+2)*i=(3×33+2)×10=1010(microseconds), which can be considered as 1 millisecond

*******************************************************/

void delay1ms()

{

   unsigned char i,j; 

  for(i=0;i<10;i++)

   for(j=0;j<33;j++)

    ;   

}

/************************************************************

Function: Delay for several milliseconds

Entry parameter: n

*******************************************************/

void delaynms(unsigned char n)

{

   unsigned char i;

for(i=0;i    delay1ms();

}

/************************************************************

Function: Read data from the current address of X5045

Export parameter: x

*******************************************************/

unsigned char ReadCurrent(void)

{

   unsigned char i;

unsigned char x=0x00; //Store the data read from X5045

SCK=1; //Put SCK in a known high state

   for(i = 0; i < 8; i++)

{

    SCK=1; //Pull SCK high

    SCK=0; //Output data on the falling edge of SCK 

    x<<=1; //Shift each binary bit in x one position to the left, because the highest bit of the byte is read first    

  x|=(unsigned char)SO; //Store the data on SO into x through bitwise "OR" operation      

}

return(x); //Return the read data

}

/************************************************************

Function: Write data to the current address of X5045

Entry parameter: dat

*******************************************************/

void WriteCurrent(unsigned char dat)

{

   unsigned char i;

SCK=0; //Put SCK in a known low state

  for(i = 0; i < 8; i++) // Loop through 8 bits

{

  SI=(bit)(dat&0x80); //Send the highest bit data to S through bitwise "AND" operation

                      //Because the high bit is in front and the low bit is in the back when transmitting

  SCK=0;

  SCK=1; //Write data on the rising edge of SCK

    dat<<=1; //Shift each binary bit in y one position to the left, because the highest bit of the byte is written first

  }

}

/************************************************************

Function: Write status register, can set watchdog overflow time and data protection

Entry parameter: rs; //Store register status value

*******************************************************/

void WriteSR(unsigned char rs)

{

  CS=0; //Pull CS low and select X5045

  WriteCurrent(WREN); //Write enable latch allows

  CS=1; //Pull CS high

  CS=0; //Pull CS low again, otherwise the following write register status instruction will be discarded

  WriteCurrent(WRSR); //Write status register

  WriteCurrent(rs); //Write the newly set register status value

  CS=1; //Pull CS high

}

/************************************************************

Function: Write data to the specified address of X5045

Entry parameter: addr

*******************************************************/

void WriteSet(unsigned char dat,unsigned char addr)

{

   SCK=0; //Put SCK in a known state

   CS=0; //Pull CS low and select X5045

WriteCurrent(WREN); //Write enable latch allows

CS=1; //Pull CS high

   CS=0; //Pull CS low again, otherwise the following write instruction will be discarded

WriteCurrent(WRITE); //Write instruction

WriteCurrent(addr); //Write to the specified address

WriteCurrent(dat); //Write data

CS=1; //Pull CS high

   SCK=0; //Put SCK in a known state

}

/************************************************************

Function: Read data from the specified address of X5045

Entry parameter: addr

Export parameter: dat

*******************************************************/

unsigned char ReadSet(unsigned char addr)

{

unsigned char dat;

SCK=0; //Put SCK in a known state

CS=0; //Pull CS low and select X5045

WriteCurrent(READ); //Start reading

WriteCurrent(addr); //Write to the specified address

dat=ReadCurrent(); //Read data

CS=1; //Pull CS high

SCK=0; //Put SCK in a known state

return dat; //Return the read data

}

/************************************************************

Function: Watchdog reset program

*******************************************************/

void WatchDog(void)

{

CS=1; //Pull CS high

CS = 0; //A falling edge on the CS pin resets the watchdog timer

……………………