spi.c

sunplus spca514 cdmp3 源码

//SPI initialisation
// clock rate: 2000000hz
#include "iom163.h"
#include <macros.h>
#define SPI_WAIT_COMMAND 0
#define SPI_WRITE_LOW    1
#define SPI_WRITE_HIGH   2
#define SPI_READ_LOW     3
#define SPI_READ_HIGH    4
#define SPI_ERR			 5
unsigned char vfd_address=0;
unsigned char spi_command=0;
extern unsigned char g_vfd_grid_buffer[];
//unsigned char buffer[24];
extern unsigned int dvd_key;
void spi_err(void);
void spi_init(void)
{
 SPCR= 0x00; //diable spi
 SPSR= 0x00; //2X
 //SPCR= 0xEC; //setup SPI CPOL:1;CPHA:1;
}

#pragma interrupt_handler spi_stc_isr:11
void spi_stc_isr(void)
{
 //byte in SPDR has been sent/received
 register unsigned char spi_status,spi_data,i;
 //SPCR &=0x7f; //disable spi interrupt 
 spi_status = SPSR;
 spi_data = SPDR;
 //Set_FS2(0);
 //Set_FS1(1);
 if(spi_status&0x40)
 {
   spi_err();
   return;
 };
 switch(spi_command)
 {
  case SPI_WAIT_COMMAND:
	   	if((spi_data&0xC3)==0x42)
		{  //read key
		  asm("SBI 0x17,6");
		  SPDR =(unsigned char)dvd_key;
		  spi_command= SPI_READ_LOW;
		}
		else if((spi_data&0xC0)==0xc0)
		{ //write
		  vfd_address = spi_data&0x3f;
		  spi_command = SPI_WRITE_LOW;
		}
		else
		  spi_err();
  	   break;
  case SPI_READ_LOW:
  	   SPDR = (unsigned char)(dvd_key>>8);
	   spi_command = SPI_READ_HIGH;
       break;
  case SPI_READ_HIGH:
       spi_command = SPI_WAIT_COMMAND;
	   dvd_key =0xffff;
	   asm("CBI 0x17,6");
       break;
  case SPI_WRITE_LOW:
	   g_vfd_grid_buffer[vfd_address] = spi_data;
	   vfd_address++;
	   spi_command = SPI_WRITE_HIGH;
       break;
  case SPI_WRITE_HIGH:
	   g_vfd_grid_buffer[vfd_address] = spi_data;
	   //if(vfd_address>22)
	    //for(i=0;i++;i<24)
		  //g_vfd_grid_buffer[i] = buffer[i];
	   spi_command = SPI_WAIT_COMMAND;
	   break;
 
  default:
  	  // Set_FS2(0);
       spi_err();
	   break;
 }
 //SPCR |=0x80;
}
void spi_err(void)
{
 unsigned int delay;
 
 SPCR =00;
 SPSR =00;
 SEI();
 SPDR = 0xff;
 asm("CBI 0X17,6");
 //dvd_key = 0xffff;
 //DI();
 delay=50000;
 //Set_FS1(0);
 while(!(PINB&0x10))
 {
  if(!delay) break;
  soft_delay();
  delay--;
 }
 SPCR = 0xec;
 delay =SPDR;
 delay=SPSR;
 //delay=SPDR;
 spi_command = SPI_WAIT_COMMAND;


}