TLSR8258F512 embeds audio module, which supports 4 types of audio input path: digital microphone(DMIC), Codec(I2S), USB, Analog microphone(AMIC). And there are 3 types of audio output path: USB, Codec(I2S), Sigma-Delta Modulation (SDM) DAC. Besides, the Audio Module of TLSR8258F512 intergrates a input processing module including Decimation filter, LPF, Down-Sample, HPF, ALC. The specific details are shown below.
A programmable stereo PGA(Programmable Gain Amplifier) with adjustable gain is built in for AMIC. AMIC input channel can carry out signal amplification via the PGA. After implementing AD conversion for selected AMIC input signal, data of 3 analog channels(CH0 ~ CH2) will be generated. Data of CH0/CH1 are sent to the audio input processing module, while data of CH2 are directly written into FIFO.
Stereo digital microphone(DMIC) interface is also supported in the TLSR8258F512. DMIC interface includes one configurable clock line and one data line. User can set the rising or falling edge of clock signal at which to sample data of DMIC by the related API. After data sampling of DMIC interface, sign extension and audio input processing, the signal can be written into FIFO.
Digital I2S audio interface supports Master mode only, 16-bit data width, and variable sampling rate: 8K/16K/22.05K/24K/32K/44.1K/48K. The sampling rate is determined by I2S clock.
TLSR8258F512 embeds I2S module including I2S Recorder and I2S Player. I2S interface includes one configurable clock line, one data line and one channel selection line. Data generated by the audio codec will be written into FIFO after implementing conversion via I2S Recorder and audio input processing.
User can select USB Host as audio input. Packet transmitted by USB Host will be written into FIFO after implementing conversion via USB interface and audio input processing.
For any type of audio input path, the data will be finally written into DMA FIFO(DFIFO )0,1 or 2.DFIFO supports auto mode and manual mode. It's highly recommended to select auto mode.
| Data Path | Target SRAM | |||
|---|---|---|---|---|
| DFIFO0 | DFIFO1 | DFIFO2 | ||
| DMIC | Decimation filter/LPF/Down Sample/HPF/ALC | • | • | × |
| I2S | • | • | × | |
| USB | • | • | × | |
| Analog CH0 | • | • | × | |
| Analog CH1 | • | • | × | |
| Analog CH2 | × | × | • | |
Audio input processing mainly includes configurable decimation filter, LPF(Low Pass Filter), Down-sample module, HPF(High Pass Filter) and ALC (Automatic Level Control). all these modules can be enabled or disabled respectively.
The decimation filter serves to down-sample the mono or stereo input (e.g. DMIC) data to required audio data playback rate(e.g. 48K or 32K). Down-sampling rate is configurable as 1 ~ 8, 16, 32, 64, 128 or 256 by the related API.
The LPF serves to conduct frequency compensation.
If the Down-sample module is enabled by the related API, it will down-sample the data from LPF with fixed ratio of 2.
The HPF serves to eliminate internal DC offset to ensure audio amplifcation range.
The ALC supports analog mode and digital mode, and it mainly serves to regulate input volume level automaitcally or manually in each mode.
The analog mode is designed only for AMIC input, while the digital mode applies to all audio input types.
In analog mode, input volume level is regualted via PGA; while in digital mode, input volume level is regulated via Multiplier/Divider.
Audio output path mainly includes USB, SDMDAC(sigma-Delta Modulation DAC) and I2S player.
In order to facilitate users to quickly develop products according to their own needs, TSI provide the following related APIs and examples.
| APIs list | Description | Example | Update Date | Status |
|---|---|---|---|---|
| audio_config_mic_buf() | set address and size of buffer for AMIC or DMIC | API-AUDIO-CASE1 | 2019-1-10 | Done |
| audio_set_dmic_clk() | set clock frequency for DMIC | API-AUDIO-CASE4 | 2019-1-10 | Done |
| audio_set_i2s_clk() | set clock frequency for I2S | API-AUDIO-CASE3 | 2019-1-10 | Done |
| audio_amic_init() | initiate AMIC as audio input path | API-AUDIO-CASE2 | 2019-1-10 | Done |
| audio_dmic_init() | initiate DMIC as audio input path | API-AUDIO-CASE5 | 2019-1-10 | Done |
| audio_usb_init() | initiate USB as audio input path | API-AUDIO-CASE9 | 2019-1-10 | Done |
| audio_i2s_init() | initiate I2S as audio input path | API-AUDIO-CASE7 | 2019-1-10 | Done |
| audio_set_usb_output() | set USB as audio output path | API-AUDIO-CASE1 | 2019-1-10 | Done |
| audio_set_i2s_output() | set I2S as audio output path | API-AUDIO-CASE3 | 2019-1-10 | Done |
| audio_set_sdm_output() | set SDM as audio output path | API-AUDIO-CASE5 | 2019-1-10 | Done |
TSI provides the following examples of this module to help users quickly understand and apply related modules.
| Examples list | Description | Update Date | Status |
|---|---|---|---|
| API-AUDIO-CASE1 | AMIC To USB | 2019-1-10 | Done |
| API-AUDIO-CASE2 | AMIC To SDM | 2019-1-10 | Done |
| API-AUDIO-CASE3 | AMIC To I2S | 2019-1-10 | Done |
| API-AUDIO-CASE4 | DMIC To USB | 2019-1-10 | Done |
| API-AUDIO-CASE5 | DMIC To SDM | 2019-1-10 | Done |
| API-AUDIO-CASE6 | DMIC To I2S | 2019-1-10 | Done |
| API-AUDIO-CASE7 | I2S To USB | 2019-1-10 | Done |
| API-AUDIO-CASE8 | I2S To SDM | - | Todo |
| API-AUDIO-CASE9 | USB To SDM | 2019-1-10 | Done |
| API-AUDIO-CASE10 | USB To I2S | - | Todo |
| Date | Description | Author |
|---|---|---|
| 2019-1-10 | initial release | LJW |
| 2019-8-15 | update api name for application | LJW |