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NK-980IOT测评之I2S接口音频测试

发布于 2022-03-14 20:30:52 浏览：2470 订阅该版

[tocm]

# 特征
- 支持I2S和PCM接口,支持8/16/18/20/24bit,两通道。
- 18/20/24-bit模式时,每个通道的数据存储在32bit字中,高位有效,低位补零。
- 16位模式时,右通道存储在32bit字的高16位,左通道存储在低16位。
- 支持DMA一次传输4/8/16拍后总线锁定,传输1/8,1/4,1/2或者传输完成时可以产生中断。16位精度时,一次传输8拍或者4拍;24/20/18位精度时,一次传输16或者8拍。
- 使用AHB端口,I2S支持主从,PCM只支持主。
- 支持双地址
![image.png](https://oss-club.rt-thread.org/uploads/20220314/bafd363220707bf4b96b716b26509808.png.webp)
# 配置
- 时钟使能
CLK_HCLKEN[24],写1使能。
时钟源如下:
![image.png](https://oss-club.rt-thread.org/uploads/20220314/fb4bf7fa000590e0e771cbff3da401ec.png.webp)
- 复位模块
SYS_AHBIPRST[8],写1复位,写0结束复位。
- 引脚配置
![image.png](https://oss-club.rt-thread.org/uploads/20220314/c750b170dc1c890b6bdaba632e202f0b.png.webp)

# I2S接口
I2S主
![image.png](https://oss-club.rt-thread.org/uploads/20220314/ae0ac37389903e7d9ff0746677ac82b0.png.webp)

I2S从
![image.png](https://oss-club.rt-thread.org/uploads/20220314/6bdb9cf699a23bde69022aa0a2b0fd07.png.webp)
时序
高位对齐,左对齐
![image.png](https://oss-club.rt-thread.org/uploads/20220314/8a77fc4804aa09e5169dc96a26173a00.png.webp)

# PCM接口
![image.png](https://oss-club.rt-thread.org/uploads/20220314/fb2e1083f6eab3a902ad499595d9d435.png.webp)

时序
![image.png](https://oss-club.rt-thread.org/uploads/20220314/1429c5cd405a5dfd0503f09a0a6f68aa.png.webp)
# 数据格式

![image.png](https://oss-club.rt-thread.org/uploads/20220314/48ddc80cbde7c5410ba501d42676bbb8.png)
# 寄存器
以下是简介详见手册:
- I2S_GLBCON
设置中断,精度,FIFO阈值,使能I2S或PCM。
- I2S_RESET
设置数据格式,复位控制,录音和播放的通道选择,录音和播放的使能,
- I2S_RDESB
记录DMA基地址
- I2S_RDES_LENGTH
记录DMA数据长度
- I2S_RDESC
记录DMA当前地址
- I2S_PDESB
播放DMA基地址
- I2S_PDES_LENGTH
播放DMA数据长度
- I2S_PDESC
播放DMA当前地址
- 记录状态寄存器
I2S_RSR
- I2S_PSR
播放状态寄存器
- I2S_CON
设置I2S主从模式,频率设置,时钟选择对齐格式。
- I2S_COUNTER
播放DMA数据计数器
- I2S_PCMCON
PCM参数设置
- I2S_PCMS1ST
PCM通道1数据位置设置
- I2S_PCMS2ST
PCM通道1数据位置设置
- I2S_RDESB2
记录DMA目的地址2
- I2S_PDESB2
播放MDA目的地址2

# 硬件资源
![image.png](https://oss-club.rt-thread.org/uploads/20220314/40da16a59297af0224eb91c6532494cc.png.webp)
![image.png](https://oss-club.rt-thread.org/uploads/20220314/071512e382c16eb81584fa2b3bec374c.png.webp)
![image.png](https://oss-club.rt-thread.org/uploads/20220314/18932b3cc14c1788b8349ba2235c0392.png.webp)
音频芯片型号为NAU8822L,其中I2C接口用于配置(MODE引脚低),I2S接口用于传输数据。
I2S_LRCK接FS,用于区分左右通道数据。
I2S_BCLK接BCLK  数据传输bit时钟。
I2S_DI接ADCOUT 主<-从。
I2S_DO接ADCIN  主->从。
I2S_MCLK接MCLK 主时钟,给设备提供时钟源。

## IIC接口
写寄存器过程
START->发送0x34->等待ACK->发送寄存器地址->等待ACK->发送字节数据源->等待ACK->STOP
![image.png](https://oss-club.rt-thread.org/uploads/20220314/a522e8bd8150834752d5fe3f79626252.png.webp)
读寄存器过程
START->发送0x34(写)->等待ACK->发送寄存器地址->等待ACK->START
->发送0x35(读)->等待ACK->读数据->发送ACK->读数据->发送NACK->STOP
![image.png](https://oss-club.rt-thread.org/uploads/20220314/7e4b636361ee9672aec27af64fdef31d.png.webp)
寄存器详见手册P69
14 Appendix C: Details of Register Operation

## I2S接口
![image.png](https://oss-club.rt-thread.org/uploads/20220314/eb14a48638e83bdacc8e07b1baa7d727.png.webp)

# 驱动
I2C驱动见`\components\drivers\i2c`
I2S驱动见`\bsp\nuvoton\libraries\nuc980\rtt_port\drv_i2s.c`

参见https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/device/audio/audio
主要API
```
rt_err_t res;
				snd_dev = rt_device_find("sound0");     /* 根据设备名称查找 Audio 设备，获取设备句柄 */
			  if(RT_NULL == snd_dev)
				{
						return;
				}
				res = rt_device_open(snd_dev, RT_DEVICE_OFLAG_WRONLY | RT_DEVICE_FLAG_RDONLY);
				if(RT_EOK != res)
				{
						return;
				}
				/* 设置播放的采样率、采样通道、以及采样位数 */
				struct rt_audio_caps caps;
				caps.main_type               = AUDIO_TYPE_OUTPUT; /* 输出类型（播放设备 ）*/
				caps.sub_type                = AUDIO_DSP_PARAM;   /* 设置所有音频参数信息 */
				caps.udata.config.samplerate = 44100;             /* 采样率 */
				caps.udata.config.channels   = 2;                 /* 采样通道 */
				caps.udata.config.samplebits = 16;                /* 采样位数 */
				res = rt_device_control(snd_dev, AUDIO_CTL_CONFIGURE, &caps);
				/* 设置播放的主音量*/
				caps.main_type   = AUDIO_TYPE_MIXER;       /* 音量管理类型 */
				caps.sub_type    = AUDIO_MIXER_VOLUME;     /* 设置播放的主音量 */
				caps.udata.value = 100;                    /* 范围 0 ~ 100 */
				res = rt_device_control(snd_dev, AUDIO_CTL_CONFIGURE, &caps);
				/* 设置录音的采样率、采样通道、以及采样位数 */
				caps.main_type               = AUDIO_TYPE_INPUT;  /* 输入类型（录音设备 ）*/
				caps.sub_type                = AUDIO_DSP_PARAM;   /* 设置所有音频参数信息 */
				caps.udata.config.samplerate = 44100;             /* 采样率 */
				caps.udata.config.channels   = 2;                 /* 采样通道 */
				caps.udata.config.samplebits = 16;                /* 采样位数 */
				res = rt_device_control(snd_dev, AUDIO_CTL_CONFIGURE, &caps);
				/* 设置录音的主音量 */
				caps.main_type = AUDIO_TYPE_MIXER;       /* 音量管理类型 */
				caps.sub_type  = AUDIO_MIXER_MIC;        /* 设置录音的主音量 */
				caps.udata.value = 100;               /* 范围 0 ~ 100 */
				rt_device_control(snd_dev, AUDIO_CTL_CONFIGURE, &caps);
				
				/* 写数据 */
				//rt_size_t rt_device_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size);
				/* 读数据*/
				//rt_size_t rt_device_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size);
				/* 关闭设备*/
				//rt_err_t rt_device_close(rt_device_t dev);
```

# 测试

## 播放代码解析
INIT_APP_EXPORT(wavplayer_init);
导出变量__rt_init_wavplayer_init 到.rti_fn.6段,值是wavplayer_init,
map文件可以看到

![image.png](https://oss-club.rt-thread.org/uploads/20220314/407416e4ed7708a521fb69a954fafea8.png.webp)

main_thread_entry->rt_components_init->wavplayer_init->wavplayer_entry
等待事件player:PLAYER_EVENT_PLAY

MSH_CMD_EXPORT_ALIAS(wav_player, wavplay, play wav music);
注册命令,当SH输入wavplay时调用wav_player,处理。
解析调用wavplayer_xxx接口处理。
比如-s 就START调用的是wavplayer_play发送消息play_msg_send,player。

wavplayer_entry等到事件,调用wavplayer_open,
先查找设备rt_device_find sound0
然后打开设备rt_device_open
最后配置参数rt_device_control

然后读文件fread,发送数据rt_device_write。

rt_hw_nau8822_port->nu_hw_nau8822_init找到I2C设备g_I2cBusDev
I2C_WriteNAU8822,I2C_ReadNAU8822实现读写寄存器

NAU8822驱动(只初始化使用,读写直接通过I2S设备驱动)
INIT_COMPONENT_EXPORT(rt_hw_nau8822_port);
rt_hw_nau8822_port->nu_hw_nau8822_init->nu_acodec_ops_nau8822->nau8822_dsp_control->nau8822_dsp_config

rt_hw_i2s_init时绑定了    rt_audio_register(&g_nu_i2s_dev.audio, g_nu_i2s_dev.name, RT_DEVICE_FLAG_RDWR, &g_nu_i2s_dev);
audio设备。

## Demo
`\bsp\nuvoton\nk-980iot\packages\wavplayer-latest\src`下有wavplayer的demo。

输入wavrecord -s test.wav 8000 2 16   录音到test.wav文件,采样率8000,双通道,16bit。

wavrecord -t  停止录音
wavplay -s test.wav开始播放
wavplay -t 停止播放
```
msh />wavrecord -s test.wav 8000 2 16  
I2S stop recording
[I/i2s] Stop record.
[I/i2s] Close I2S.
Wrote addr 00 -> 0x0000, read back -> 0x0000
msh />[I/acodec.nau8822] Software Reset.

Wrote addr 01 -> 0x003f, read back -> 0x003f
Wrote addr 02 -> 0x01bf, read back -> 0x01bf
Wrote addr 03 -> 0x007f, read back -> 0x006f
Wrote addr 04 -> 0x0010, read back -> 0x0010
Wrote addr 05 -> 0x0000, read back -> 0x0000
Wrote addr 06 -> 0x01ad, read back -> 0x01ad
Wrote addr 07 -> 0x0006, read back -> 0x0006
Wrote addr 0a -> 0x0008, read back -> 0x0008
Wrote addr 0e -> 0x0108, read back -> 0x0108
Wrote addr 0f -> 0x01ef, read back -> 0x00ef
Wrote addr 10 -> 0x01ef, read back -> 0x00ef
Wrote addr 2c -> 0x0033, read back -> 0x0033
Wrote addr 2f -> 0x0100, read back -> 0x0100
Wrote addr 30 -> 0x0100, read back -> 0x0100
Wrote addr 32 -> 0x0001, read back -> 0x0001
Wrote addr 33 -> 0x0001, read back -> 0x0001
Wrote addr 34 -> 0x013f, read back -> 0x003f
Wrote addr 35 -> 0x013f, read back -> 0x003f
[I/acodec.nau8822] Initialized done.

Wrote addr 24 -> 0x0008, read back -> 0x0008
Wrote addr 25 -> 0x000c, read back -> 0x000c
Wrote addr 26 -> 0x0093, read back -> 0x0093
Wrote addr 27 -> 0x00e9, read back -> 0x00e9
Wrote addr 04 -> 0x0010, read back -> 0x0010
Wrote addr 06 -> 0x01ed, read back -> 0x01ed
[I/i2s] Open I2S.
Wrote addr 0a -> 0x0800, read back -> 0x0008
IIS start recording...
[I/i2s] Start record.
Information:
samplerate 8000
channels 2
msh />wavrecord -t                   
I2S stop recording
[I/i2s] Stop record.
[I/i2s] Close I2S.
msh />wavplay -s test.wav
Wrote addr 0b -> 0x008c, read back -> 0x00ff
Wrote addr 0c -> 0x008c, read back -> 0x00ff
[I/WAV_PLAYER] play start, uri=test.wav
IIS stop playing
[I/i2s] Stop replay.
[I/i2s] Close I2S.
Wrote addr 00 -> 0x0000, read back -> 0x0000
msh />[I/acodec.nau8822] Software Reset.

Wrote addr 24 -> 0x0008, read back -> 0x0008
Wrote addr 25 -> 0x000c, read back -> 0x000c
Wrote addr 26 -> 0x0093, read back -> 0x0093
Wrote addr 27 -> 0x00e9, read back -> 0x00e9
Wrote addr 04 -> 0x0010, read back -> 0x0010
Wrote addr 06 -> 0x01ed, read back -> 0x01ed
[I/i2s] Open I2S.
Wrote addr 0a -> 0x0800, read back -> 0x0008
IIS start playing...
[I/i2s] Start replay.
IIS stop playing
[I/i2s] Stop replay.
[I/i2s] Close I2S.
[I/WAV_PLAYER] play end
msh />wavplay -t         
msh />
```
输入sy test.wav回车 CRT,【传输】-【接收Ymodem】到处文件到电脑。
如果没有sy,则添加`\rt-thread\components\utilities\ymodem`下的源码
![image.png](https://oss-club.rt-thread.org/uploads/20220314/017db8b68d1ce18e79e9df589f7a5ce4.png.webp)

见附件:
[test.wav](https://oss-club.rt-thread.org/uploads/20220314/8c821b148e87aa7bfe6aec004404da27.wav)