pcm1770.c

凌阳MP3 spSPCA755yuanma

//#include "general.h
#include <reg320.h>
//#include <stdio.h>
sbit  DbgP17 = P1^7 ;
sbit  DbgP12 = P1^2;
sbit  DbgP10 = P1^0;

#define MD   DbgP17
#define MC   DbgP12
#define MS   DbgP10

void delay_us(unsigned char i)
{
 unsigned char j;
 for(j=0;j<i;j++)
 {
 };
}

void pcm1770_word_write(unsigned int val)
{
  unsigned char i;
  MS = 1;
  MC = 0;
  delay_us(10);
  MS = 0;
  for(i=0;i<16;i++)
  {
    if(val&0x8000)
	 MD = 1;
	else
	 MD  = 0;
	val <<=1;
	MC = 1;
	delay_us(5);
	MC = 0;
  }
  delay_us(10);
  MS = 1;
}
/*
void pcm1770_mute(unsigned char val)
{
  if(val)
  {
    pcm1770_word_write(0x01c0);
    pcm1770_word_write(0x0200);
  }
  else
  {
   pcm1770_word_write(0x013f);
   pcm1770_word_write(0x023f);
  };
}*/
void init_pcm1770(void)
{
  pcm1770_word_write(0x0304);  //16bit right justify
  pcm1770_word_write(0x013f);
  pcm1770_word_write(0x023f);
}