音量控制M62446的驱动C程序

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音量控制M62446的驱动C程序

音量控制M62446 m62446 pdf

//-------------------------------------------------------------------------

// M62446 drving routines, VER 1.0

// Target: 8031

// AUTHOR: STEVEN LUO

// Revision History:

// 2001/1/5 - Original Version

//-------------------------------------------------------------------------

#include

extern BOOL PIN_M62446_LATCH;

extern BOOL PIN_M62446_DATA;

extern BOOL PIN_M62446_CLK;

static idata WORD shadow_word00=0;

static idata WORD shadow_word01=0;

static idata WORD shadow_word10=0;

static idata WORD shadow_word11=0; // for storing the control word status // static BOOL bM62446Muted; // Set when 62446 is muted

static void Write_M62446_Word(WORD myword);

//-------------------------------------------------------------------------

// Name: Volume_Validate

// Description:

// Arguments:

// Return value: none

//-------------------------------------------------------------------------

static BYTE Volume_Validate(char vol){

if(vol<0)vol=0; // negative, should be 0

else if(vol >80) vol=80; // >80, set to 80

return 80 - vol; // Down to Up

}

//-------------------------------------------------------------------------

// Name: Mute_M62446

// Description:

// Arguments:

// Return value: none

//-------------------------------------------------------------------------

void Mute_M62446(void){

Write_M62446_Word(0xa141); // B1010000 1010000 01, B10100001_01000001

Write_M62446_Word(0xa142);

Write_M62446_Word(0xa143);

bM62446Muted = 1;

}

//-------------------------------------------------------------------------

// Name: UnMute_M62446

// Description:

// Arguments:

// Return value: none

//-------------------------------------------------------------------------

void UnMute_M62446(void){

shadow_word01&=0xfffc; shadow_word01|=0x01; Write_M62446_Word(shadow_word01); shadow_word10&=0xfffc; shadow_word10|=0x02; Write_M62446_Word(shadow_word10); shadow_word11&=0xfffc; shadow_word11|=0x03; Write_M62446_Word(shadow_word11);

bM62446Muted = 0;

}

//-------------------------------------------------------------------------

// Name: Write_M62446_Left

// Description: This function Write 2 bytes to M62446

// Arguments:

// Return value: none

//-------------------------------------------------------------------------

void Write_M62446_Left(char vol){

WORD temp;

temp=Volume_Validate(vol);

temp<<=9;

shadow_word01&=0x01ff;

shadow_word01|=temp;

// DE=0;DF=1;

shadow_word01&=0xfffc; shadow_word01|=0x01;

if (bM62446Muted) return;

Write_M62446_Word(shadow_word01);

}

//-------------------------------------------------------------------------

// Name: Write_M62446_Right

// Description: This function Write 2 bytes to M62446

// Arguments:

// Return value: none

//-------------------------------------------------------------------------

void Write_M62446_Right(char vol){

WORD temp;

temp=Volume_Validate(vol);

temp<<=2;