ARM7 Getting Started 12, SPI Communication

Main program:

/*******************************************************************************
*File: Main.c
*Function: The LED digital tube displays characters 0-F, and controls 4 LEDs to display the corresponding hexadecimal
******************************************************************************/
#include "config.h"
#define HC595_CS 0x00000100 /*P0.8 port is the chip select of 74HC595*/
uint8 rcv_data;
/***********************************************************************************
*Name: DelayNS()
*Function: Long software delay
******************************************************************************/
void DelayNS(uint32 dly)
{ uint32 i;
   for (;dly>0;dly--)
      for(i=0;i<50000;i++);
}
/*******************************************************************************
*Name: MSpiIni()
*Function: Initialize SPI interface and set it as host
****************************************************************************/
void MSpiIni(void)
{ S0PCCR=0x52; //Set SPI clock division
  S0PCR=0x30; //Set SPI interface mode, MSTR=1, CPOL=1, CPHA=0, LSBF=0
}
/***********************************************************************************
*Name: MSendData()
*Function: Send data to SPI bus
***************************************************************************/
uint8 MSendData(uint8 data)
{ IO0CLR=HC595_CS; //Chip select
  S0PDR=data;
  while(0==(S0PSR&0x80)); //Wait for SPIF to be set, that is, wait for data to be sent
  IO0SET=HC595_CS;
  return(S0PDR);
}
/*This table is the font of 0~F*/
  uint8 const DISP_TAB[16]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90,
                            0x88,0x83,0xC6,0xA1,0x86,0x8E};
/*******************************************************************************
*Name: main()
*Function: Use the hardware SPI interface to output data from 0~F and control the LED display
*******************************************************************************/

int main(void)
{ 
  uint8 i;  
  
  PINSEL0=0x00005500; //Set SPI pin connection
  PINSEL1=0x00000000;
  
  IO0DIR=HC595_CS; 
  MSpiIni(); //Initialize SPI interfacewhile
  (1)
  { for (i=0;i<16;i++) 
    {rcv_data=MSendData(DISP_TAB[i]); //Send display data
      DelayNS(50); //Delay
    }
  }
  
}