TLV320AIC23B MIC产生回音，求助！

我司用TLV320AIC23B设计，耳机在对讲时会有回音，经过测试发现MIC信号有干扰，单板测出正常，但是接上耳机会有0.9mVrms的电压，现在解决了串扰不失真，但是回音仍然存在，求指导！谢谢！调试电阻电容是否会有改善？

Jacky Wang(QD)：

MIC与耳机听筒距离是否距离较近，MICBIAS去耦电容C61去掉。MIC和耳机听筒是共用一个连接器吗？有无接触不良？

xu huizeng：

回复 Jacky Wang(QD):

mic和耳机距离不近，板子到mic还有一根转接线连接的，不是普通那种pcb上接连接器那种。不是连接器不良，对了，那个mic的地我与板子上的大地都是连在一起的，也就是说并没有分agnd,dgnd. 这样回路会有很大影响吗？

Jacky Wang(QD)：

回复 xu huizeng:

理论上讲会有一些影响，但不至于到产生回声这种级别。有没有换个耳机试试？

另外方便的话把你完整的电路和PCB文件发上来看看。

JINGWEI WANG3：

回复 xu huizeng:

您的mic功能是怎么实现的呀？？？我这边改了部分程序内容还是没反应，是不是寄存器要改呀！！！下面是我改的程序，求指教！！！

#include <csl.h>#include <csl_i2c.h>#include <stdio.h>#include <csl_pll.h>#include <csl_mcbsp.h>

#define CODEC_ADDR 0x1A

/*锁相环的设置*/PLL_Config myConfig = { 0, //IAI: the PLL locks using the same process that was underway //before the idle mode was entered 1, //IOB: If the PLL indicates a break in the phase lock, //it switches to its bypass mode and restarts the PLL phase-locking //sequence 12, //PLL multiply value; multiply 24 times 1 //Divide by 2 PLL divide value; it can be either PLL divide value //(when PLL is enabled), or Bypass-mode divide value //(PLL in bypass mode, if PLL multiply value is set to 1)};

MCBSP_Config Mcbsptest;

/*McBSP set,we use mcbsp1 to send and recieve the data between DSP and AIC23*/MCBSP_Config Mcbsp1Config = { MCBSP_SPCR1_RMK( MCBSP_SPCR1_DLB_OFF, /* DLB = 0,禁止自闭环方式 */ MCBSP_SPCR1_RJUST_LZF, /* RJUST = 2 */ MCBSP_SPCR1_CLKSTP_DISABLE, /* CLKSTP = 0 */ MCBSP_SPCR1_DXENA_ON, /* DXENA = 1 */ 0, /* ABIS = 0 */ MCBSP_SPCR1_RINTM_RRDY, /* RINTM = 0 */ 0, /* RSYNCER = 0 */ MCBSP_SPCR1_RRST_DISABLE /* RRST = 0 */ ), MCBSP_SPCR2_RMK( MCBSP_SPCR2_FREE_NO, /* FREE = 0 */ MCBSP_SPCR2_SOFT_NO, /* SOFT = 0 */ MCBSP_SPCR2_FRST_FSG, /* FRST = 0 */ MCBSP_SPCR2_GRST_CLKG, /* GRST = 0 */ MCBSP_SPCR2_XINTM_XRDY, /* XINTM = 0 */ 0, /* XSYNCER = N/A */ MCBSP_SPCR2_XRST_DISABLE /* XRST = 0 */ ), /*单数据相，接受数据长度为16位,每相2个数据*/ MCBSP_RCR1_RMK( MCBSP_RCR1_RFRLEN1_OF(1), /* RFRLEN1 = 1 */ MCBSP_RCR1_RWDLEN1_16BIT /* RWDLEN1 = 2 */ ), MCBSP_RCR2_RMK( MCBSP_RCR2_RPHASE_SINGLE, /* RPHASE = 0 */ MCBSP_RCR2_RFRLEN2_OF(0), /* RFRLEN2 = 0 */ MCBSP_RCR2_RWDLEN2_8BIT, /* RWDLEN2 = 0 */ MCBSP_RCR2_RCOMPAND_MSB, /* RCOMPAND = 0 */ MCBSP_RCR2_RFIG_YES, /* RFIG = 0 */ MCBSP_RCR2_RDATDLY_1BIT /* RDATDLY = 1 */ ), MCBSP_XCR1_RMK( MCBSP_XCR1_XFRLEN1_OF(1), /* XFRLEN1 = 1 */ MCBSP_XCR1_XWDLEN1_16BIT /* XWDLEN1 = 2 */ ), MCBSP_XCR2_RMK( MCBSP_XCR2_XPHASE_SINGLE, /* XPHASE = 0 */ MCBSP_XCR2_XFRLEN2_OF(0), /* XFRLEN2 = 0 */ MCBSP_XCR2_XWDLEN2_8BIT, /* XWDLEN2 = 0 */ MCBSP_XCR2_XCOMPAND_MSB, /* XCOMPAND = 0 */ MCBSP_XCR2_XFIG_YES, /* XFIG = 0 */ MCBSP_XCR2_XDATDLY_1BIT /* XDATDLY = 1 */ ), MCBSP_SRGR1_DEFAULT, MCBSP_SRGR2_DEFAULT, MCBSP_MCR1_DEFAULT, MCBSP_MCR2_DEFAULT, MCBSP_PCR_RMK( MCBSP_PCR_IDLEEN_RESET, /* IDLEEN = 0 */ MCBSP_PCR_XIOEN_SP, /* XIOEN = 0 */ MCBSP_PCR_RIOEN_SP, /* RIOEN = 0 */ MCBSP_PCR_FSXM_EXTERNAL, /* FSXM = 0 */ MCBSP_PCR_FSRM_EXTERNAL, /* FSRM = 0 */ 0, /* DXSTAT = N/A */ MCBSP_PCR_CLKXM_INPUT, /* CLKXM = 0 */ MCBSP_PCR_CLKRM_INPUT, /* CLKRM = 0 */ MCBSP_PCR_SCLKME_NO, /* SCLKME = 0 */ MCBSP_PCR_FSXP_ACTIVEHIGH, /* FSXP = 0 */ MCBSP_PCR_FSRP_ACTIVEHIGH, /* FSRP = 1 */ MCBSP_PCR_CLKXP_FALLING, /* CLKXP = 1 */ MCBSP_PCR_CLKRP_RISING /* CLKRP = 1 */ ), MCBSP_RCERA_DEFAULT, MCBSP_RCERB_DEFAULT, MCBSP_RCERC_DEFAULT, MCBSP_RCERD_DEFAULT, MCBSP_RCERE_DEFAULT, MCBSP_RCERF_DEFAULT, MCBSP_RCERG_DEFAULT, MCBSP_RCERH_DEFAULT, MCBSP_XCERA_DEFAULT, MCBSP_XCERB_DEFAULT, MCBSP_XCERC_DEFAULT, MCBSP_XCERD_DEFAULT, MCBSP_XCERE_DEFAULT, MCBSP_XCERF_DEFAULT, MCBSP_XCERG_DEFAULT, MCBSP_XCERH_DEFAULT}; /* This next struct shows how to use the I2C API *//* Create and initialize an I2C initialization structure */I2C_Setup I2Cinit = { 0, /* 7 bit address mode */ 0, /* own address – don't care if master */ 84, /* clkout value (Mhz) */ 50, /* a number between 10 and 400*/ 0, /* number of bits/byte to be received or transmitted (8)*/ 0, /* DLB mode on*/ 1 /* FREE mode of operation on*/};

I2C_Config testI2C;

/*数字音频接口格式设置AIC23为主模式，数据为DSP模式，数据长度16位*/ Uint16 digital_audio_inteface_format[2]={0x0e,0x53};/*AIC23的波特率设置，采样率为44.1K*/Uint16 sample_rate_control[2] = {0x10,0x20};/*AIC23寄存器复位*/Uint16 reset[2] ={0x1e,0x00};/*AIC23节电方式设置，所有部分均所与工作状态*/Uint16 power_down_control[2] ={0x0c,0x01};/*AIC23模拟音频的控制DAC使能，ADC输入选择为MIC*/Uint16 analog_aduio_path_control[2] ={0x08,0x15};/*AIC23数字音频通路的控制*/Uint16 digital_audio_path_control[2] ={0x0a,0x05};/*AIC23数字接口的激活*/Uint16 digital_interface_activation[2] ={0x12,0x01};/*AIC23左通路音频调节*/Uint16 left_line_input_volume_control[2] ={0x00,0x00};/*AIC23右通路音频调节*/Uint16 right_line_input_volume_control[2] ={0x02,0x00};/*AIC23耳机左通路音频调节*/Uint16 left_headphone_volume_control[2] ={0x05,0x79};/*AIC23耳机右通路音频调节*/Uint16 right_headphone_volume_control[2] = {0x07,0x79};/*定义McBSP的句柄*/MCBSP_Handle hMcbsp;

Uint16 i2c_status;Uint16 i,temp;

void delay(Uint32 k){ while(k–);}

void main(void){

Uint16 aic23data = 0; i2c_status = 1; /* Initialize CSL library – This is REQUIRED !!! */ /*初始化CSL库*/ CSL_init(); /*设置系统的运行速度为140MHz*/ PLL_config(&myConfig); /* Initialize I2C, using parameters in init structure */ /*初始化I2C的格式*/

// I2C_config(&Config);// I2C_start(); // I2C_getConfig(&Config1); /*I2C is undet reset*/ I2C_RSET(I2CMDR,0); /*设置预分频寄存器,I2C的mode clock is 10MHz*/ delay(100); I2C_RSET(I2CSAR,0x001A);

I2C_RSET(I2CMDR,0x0620); I2C_setup(&I2Cinit); /*设置Ｉ２Ｃ的Mater clock*/ I2C_RSET(I2CCLKL,100); I2C_RSET(I2CCLKH,100);

I2C_getConfig(&testI2C);

/*初始化McBSP0*/ hMcbsp = MCBSP_open(MCBSP_PORT0,MCBSP_OPEN_RESET); /*设置McBSP0*/ MCBSP_config(hMcbsp,&Mcbsp1Config); /*启动McBSP0*/ MCBSP_start(hMcbsp, MCBSP_RCV_START | MCBSP_XMIT_START, 0);

MCBSP_getConfig(hMcbsp,&Mcbsptest);

/*reset AIC23*/ i2c_status = I2C_write( reset, //pointer to data array 2, //length of data to be transmitted 1, //master or slaver–master CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); delay(1000); /*设置AIC23各部分均工作*/ i2c_status = I2C_write( power_down_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置AIC23的数字接口*/ i2c_status = I2C_write( digital_audio_inteface_format,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置AIC23模拟通路*/ i2c_status = I2C_write( analog_aduio_path_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置数字通路*/ i2c_status = I2C_write( digital_audio_path_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置AIC23的采样率*/ i2c_status = I2C_write( sample_rate_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置耳机音量*/ i2c_status = I2C_write( left_headphone_volume_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); i2c_status = I2C_write( right_headphone_volume_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*设置Line输入的音量*/ i2c_status = I2C_write( left_line_input_volume_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); i2c_status = I2C_write( right_line_input_volume_control,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*启动AIC23*/ i2c_status = I2C_write( digital_interface_activation,//pointer to data array 2, //length of data to be transmitted 1, //master or slaver CODEC_ADDR, //slave address to transmit to 1, //transfer mode of operation 30000 //time out for bus busy ); /*回放音频*/ while(TRUE) { while(!MCBSP_rrdy(hMcbsp)){};

aic23data = MCBSP_read16(hMcbsp); // while(!MCBSP_xrdy(hMcbsp)){}; MCBSP_write16(hMcbsp,aic23data); // aic23data = 500;

// for(temp=300;temp>0;temp-=1) // { // for(i=0;i<2;i++) // { // aic23data = 100; // MCBSP_write16(hMcbsp,aic23data); // delay(temp); // aic23data = 0; // MCBSP_write16(hMcbsp,aic23data); // delay(temp); // } // }

//MCBSP_write16(hMcbsp,aic23data); } }