si47xx_tx_digital_audio.c

si47xx FM 收音机的程序,通过单片机来控制搜台灯功能

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

Si47XX TX part - digital audio input mode

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

#include "Si47xx_common.h"

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

Si47XX_Power_Up()

Please note: Si47XX_power_up[] = {0x01,0xc2,0x0f};

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

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

Si47XX_Set_Property_INPUT_SAMPLE_RATE()

The input sample rate must be set to 0 before removing the
DCLK input or reducing the DCLK frequency below 2 MHz.

DLCK: 2M~40MHz!

2MHz in Si471x-A20
1MHz in Si471x-B30 and Si472x-B20 and Si4704/05-B20

32000Hz~48000Hz: 32,40,44.1,48KHz

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

T_ERROR_OP Si47XX_Set_Property_INPUT_SAMPLE_RATE(void)
{
	unsigned short loop_counter = 0;
	unsigned char Si47XX_reg_data[32];	
	unsigned char error_ind = 0;
	unsigned char Si47XX_set_property[] = {0x12,0x00,0x01,0x03,0xac,0x44};  //max:0xac44 = 44.1KHz
	
	//send CMD
 	error_ind = OperationSi47XX_2w(WRITE, &(Si47XX_set_property[0]), 6);
	if(error_ind)
		return I2C_ERROR;

	//wait CTS = 1
	do
	{	
		error_ind = OperationSi47XX_2w(READ, &(Si47XX_reg_data[0]), 1);
		if(error_ind)
			return I2C_ERROR;	
		loop_counter++;
	}
	while(((Si47XX_reg_data[0]) != 0x80) && (loop_counter < 0xff));  //loop_counter limit should guarantee at least 300us	
	
	if(loop_counter >= 0xff)
		return LOOP_EXP_ERROR;	

	return OK;

}

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

Si47XX_Set_Property_INPUT_Format()

This routine can be called any time.

default is: 
DCLK failing edge
I2S mode
stereo audio mode
16 bits
**********************************************************/

T_ERROR_OP Si47XX_Set_Property_INPUT_Format(void)
{
	unsigned short loop_counter = 0;
	unsigned char Si47XX_reg_data[32];	
	unsigned char error_ind = 0;
	unsigned char Si47XX_set_property[] = {0x12,0x00,0x01,0x01,0x00,0x00};  
	
	//send CMD
 	error_ind = OperationSi47XX_2w(WRITE, &(Si47XX_set_property[0]), 6);
	if(error_ind)
		return I2C_ERROR;

	//wait CTS = 1
	do
	{	
		error_ind = OperationSi47XX_2w(READ, &(Si47XX_reg_data[0]), 1);
		if(error_ind)
			return I2C_ERROR;	
		loop_counter++;
	}
	while(((Si47XX_reg_data[0]) != 0x80) && (loop_counter < 0xff));  //loop_counter limit should guarantee at least 300us	
	
	if(loop_counter >= 0xff)
		return LOOP_EXP_ERROR;	

	return OK;

}