I.MXRT MQS 使用

NXP管管

I.MXRT MQS 使用

MQS (Medium quality sound)功能来实现语音输出，而不是 DAC方式。使用I.MXRT的MQS功能，在开发板I.MXRT1050-EVKB上测试。MQS来产生2通道的中等音质，类似PWM方式的声音，硬件上使用数字GPIO引脚，MQS_LEFT 和 MQS_RIGHT引脚。




来自SAI3的44kHz或48kHz输入信号采用左对齐格式。MQS为低于10khz的信号提供不超过20db的信噪比目标。

硬件要求：
1.  连接 J-Link 调试器到 EVKB的 J62 接口。
2.  将耳机/扬声器接到 EVKB的 J88插口。
3.  将5V电源连接到EVKB的 J7插口。
4.  打开编译MQS工程，加载程序到开发板。
运行程序，就可以听到音乐声了。


需要在pinmux.c文件中配置的管脚：

1. #include "fsl_common.h"
   
2. #include "fsl_iomuxc.h"
   
3. #include "pin_mux.h"
   
4. 
   
5. /*FUNCTION**********************************************************************
   
6. *
   
7. * Function Name : BOARD_InitPins
   
8. * Description   : Configures pin routing and optionally pin electrical features.
   
9. *
   
10. *END**************************************************************************/

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1. void BOARD_InitPins(void) {
   
2.   CLOCK_EnableClock(kCLOCK_Iomuxc);          /* iomuxc clock (iomuxc_clk_enable): 0x03u */
   
3. 
   
4.   IOMUXC_SetPinMux(
   
5.       IOMUXC_GPIO_AD_B0_12_LPUART1_TX,        /* GPIO_AD_B0_12 is configured as LPUART1_TX */
   
6.       0U);                                    /* Software Input On Field: Input Path is determined by functionality */
   
7.   IOMUXC_SetPinMux(
   
8.       IOMUXC_GPIO_AD_B0_13_LPUART1_RX,        /* GPIO_AD_B0_13 is configured as LPUART1_RX */
   
9.       0U);                                    /* Software Input On Field: Input Path is determined by functionality */
   
10.   IOMUXC_SetPinMux(
    
11.       IOMUXC_GPIO_B0_00_MQS_RIGHT,            /* GPIO_B0_00 is configured as MQS_RIGHT */
    
12.       0U);                                    /* Software Input On Field: Input Path is determined by functionality */
    
13.   IOMUXC_SetPinMux(
    
14.       IOMUXC_GPIO_B0_01_MQS_LEFT,             /* GPIO_B0_01 is configured as MQS_LEFT */
    
15.       0U);                                    /* Software Input On Field: Input Path is determined by functionality */
    

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music.h文件用于保存录制好的语音数据，

1. #ifndef _MUSIC_H_
   
2. #define _MUSIC_H_
   
3. #define MUSIC_LEN sizeof(music)
   
4. /*
   
5.   Channels: 2
   
6.   Sample width: 16-bit
   
7.   Sample rate: 16.0 kHz
   
8.   Frames number: 240000
   
9. */
   
10. AT_NONCACHEABLE_SECTION_ALIGN_INIT(uint8_t music[], 64) ={}
    
11. #endif

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1. #include "board.h"
   
2. #include "music.h"
   
3. #include "pin_mux.h"
   
4. #include "clock_config.h"
   
5. 
   
6. #include "fsl_dmamux.h"
   
7. #include "fsl_sai_edma.h"
   
8. #include "fsl_iomuxc.h"
   
9. #include "fsl_debug_console.h"
   
10. /*******************************************************************************
    
11. * Definitions
    
12. ******************************************************************************/
    
13. /* SAI instance and clock */
    
14. #define DEMO_SAI SAI3
    
15. 
    
16. /* Select Audio PLL (786.432 MHz) as sai1 clock source */
    
17. #define DEMO_SAI_CLOCK_SOURCE_SELECT (2U)
    
18. /* Clock pre divider for sai clock source */
    
19. #define DEMO_SAI_CLOCK_SOURCE_PRE_DIVIDER (3U)
    
20. /* Clock divider for sai clock source */
    
21. #define DEMO_SAI_CLOCK_SOURCE_DIVIDER (4U)
    
22. /* Get frequency of sai clock: SAI3_Clock = 786.432MHz /(3+1)/(4+1) = 39.321MHz */
    
23. #define DEMO_SAI_CLK_FREQ (CLOCK_GetFreq(kCLOCK_AudioPllClk) / (DEMO_SAI_CLOCK_SOURCE_DIVIDER + 1U) / (DEMO_SAI_CLOCK_SOURCE_PRE_DIVIDER + 1U))
    
24. 
    
25. /* DMA */
    
26. #define DMAMUX0 DMAMUX
    
27. #define EXAMPLE_DMA DMA0
    
28. #define EXAMPLE_CHANNEL (0U)
    
29. #define EXAMPLE_SAI_TX_SOURCE kDmaRequestMuxSai3Tx
    
30. /*******************************************************************************
    
31. * Prototypes
    
32. ******************************************************************************/
    
33. static void callback(I2S_Type *base, sai_edma_handle_t *handle, status_t status, void *userData);
    
34. 
    
35. /*******************************************************************************
    
36. * Variables
    
37. ******************************************************************************/
    
38. AT_NONCACHEABLE_SECTION_INIT(sai_edma_handle_t txHandle) = {0};
    
39. edma_handle_t dmaHandle = {0};
    
40. 
    
41. static volatile bool isFinished = false;
    
42. 
    
43. /*******************************************************************************
    
44. * Code
    
45. ******************************************************************************/
    
46. 
    
47. /*
    
48. * AUDIO PLL setting: Frequency = Fref * (DIV_SELECT + NUM / DENOM)
    
49. *                              = 24 * (32 + 768/1000)
    
50. *                              = 786.432 MHz
    
51. */
    
52. const clock_audio_pll_config_t audioPllConfig = {
    
53.     .loopDivider = 32,      /* PLL loop divider. Valid range for DIV_SELECT divider value: 27~54. */
    
54.     .postDivider = 1,       /* Divider after the PLL, should only be 1, 2, 4, 8, 16. */
    
55.     .numerator = 768,       /* 30 bit numerator of fractional loop divider. */
    
56.     .denominator = 1000,    /* 30 bit denominator of fractional loop divider */
    
57. };
    
58. 
    
59. static void callback(I2S_Type *base, sai_edma_handle_t *handle, status_t status, void *userData)
    
60. {
    
61.     isFinished = true;
    
62. }
    
63. 
    
64. void configMQS(void)
    
65. {
    
66.     CCM->CCGR0 = CCM->CCGR0 & (~CCM_CCGR0_CG2_MASK) | CCM_CCGR0_CG2(3);         
    
67. /* Enable MQS hmclk. */
    
68.     IOMUXC_MQSEnterSoftwareReset(IOMUXC_GPR, true);                    /* Reset MQS. */
    
69.     IOMUXC_MQSEnterSoftwareReset(IOMUXC_GPR, false);                   /* Release reset MQS. */
    
70.     IOMUXC_MQSEnable(IOMUXC_GPR, true);                                         /* Enable MQS. */
    
71.     IOMUXC_MQSConfig(IOMUXC_GPR, kIOMUXC_MqsPwmOverSampleRate64, 0u);           
    
72. /* 78.6432MHz/64/(0+1) = 1.2288MHz，Higher frequency PWM involves less low frequency harmonic.*/
    
73. }
    
74. 
    
75. /*!
    
76. * @brief Main function
    
77. */
    
78. int main(void)
    
79. {
    
80.     sai_config_t config;
    
81.     sai_transfer_format_t format;
    
82.     sai_transfer_t xfer;
    
83.     edma_config_t dmaConfig = {0};
    
84. 
    
85.     BOARD_ConfigMPU();
    
86.     BOARD_InitPins();
    
87.     BOARD_BootClockRUN();
    
88.     CLOCK_InitAudioPll(&audioPllConfig);
    
89.     BOARD_InitDebugConsole();
    
90. 
    
91.     /*Clock setting for SAI. */
    
92.     CLOCK_SetMux(kCLOCK_Sai3Mux, DEMO_SAI_CLOCK_SOURCE_SELECT);
    
93.     CLOCK_SetDiv(kCLOCK_Sai3PreDiv, DEMO_SAI_CLOCK_SOURCE_PRE_DIVIDER);
    
94.     CLOCK_SetDiv(kCLOCK_Sai3Div, DEMO_SAI_CLOCK_SOURCE_DIVIDER);
    
95. 
    
96.     PRINTF("SAI MQS DAM example started.\n\r");
    
97. 
    
98.     /* Create EDMA handle */
    
99.     EDMA_GetDefaultConfig(&dmaConfig);
    
100.     EDMA_Init(EXAMPLE_DMA, &dmaConfig);
     
101.     EDMA_CreateHandle(&dmaHandle, EXAMPLE_DMA, EXAMPLE_CHANNEL);
     
102. 
     
103.     DMAMUX_Init(DMAMUX0);
     
104.     DMAMUX_SetSource(DMAMUX0, EXAMPLE_CHANNEL, EXAMPLE_SAI_TX_SOURCE);
     
105.     DMAMUX_EnableChannel(DMAMUX0, EXAMPLE_CHANNEL);
     
106. 
     
107.     /* Init SAI module */
     
108.     SAI_TxGetDefaultConfig(&config);
     
109.     SAI_TxInit(DEMO_SAI, &config);
     
110. 
     
111.     /* Configure the audio format */
     
112.     format.bitWidth = kSAI_WordWidth16bits;
     
113.     format.channel = 0U;
     
114.     format.sampleRate_Hz = kSAI_SampleRate16KHz;
     
115.     format.masterClockHz = DEMO_SAI_CLK_FREQ;
     
116.     format.protocol = config.protocol;
     
117.     format.stereo = kSAI_Stereo;
     
118.     format.isFrameSyncCompact = true;
     
119.     format.watermark = FSL_FEATURE_SAI_FIFO_COUNT / 2U;
     
120. 
     
121.     SAI_TransferTxCreateHandleEDMA(DEMO_SAI, &txHandle, callback, NULL, &dmaHandle);
     
122.     SAI_TransferTxSetFormatEDMA(DEMO_SAI, &txHandle, &format, DEMO_SAI_CLK_FREQ, format.masterClockHz);
     
123. 
     
124.     configMQS();
     
125. 
     
126.     /*  xfer structure */
     
127.     xfer.data = (uint8_t *)(uint32_t)music;
     
128.     xfer.dataSize = MUSIC_LEN;
     
129. 
     
130.     while (1)
     
131.     {
     
132.         isFinished = false;
     
133.         SAI_TransferSendEDMA(DEMO_SAI, &txHandle, &xfer);
     
134.         /* Wait until finished */
     
135.         while (isFinished != true)
     
136.         {
     
137.         }
     
138.     }
     
139. }

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