Datasheet ADSP-BF522C, ADSP-BF523C, ADSP-BF524C, ADSP-BF525C, ADSP-BF526C, ADSP-BF527C (Analog Devices) - 8

HerstellerAnalog Devices
BeschreibungBlackfin Embedded Processor with Codec
Seiten / Seite36 / 8 — Recording Mode. Playback Mode. Digital Audio Data Sampling Rate
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DokumentenspracheEnglisch

Recording Mode. Playback Mode. Digital Audio Data Sampling Rate

Recording Mode Playback Mode Digital Audio Data Sampling Rate

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ADSP-BF522C/ADSP-BF523C/ADSP-BF524C/ADSP-BF525C/ADSP-BF526C/ADSP-BF527C
Recording Mode
The digital audio interface sends the ADC digital filter data to the ADCDAT output pin for recording. The ADCDAT data stream multiplexes the left- and right-channel audio data in the time domain. The ADCLRC clock signal separates left- and right-channel digital audio frames on the ADCDAT lines. The CODEC_BCLK signal clocks the digital audio data within the frames. The CODEC_BCLK signal is either an input or an output depending on whether the codec is in master or slave mode. During a recording operation, ADCDAT and ADCLRC must be synchronous to the CODEC_BCLK signal to avoid data corruption.
Playback Mode
The digital audio interface receives data on the DACDAT input pin for playback. The digital audio data stream on the DACDAT pin is time-domain-multiplexed left and right channel audio data. The DACLRC clock signal separates left and right channel digital audio frames on the DACDAT lines. The CODEC_BCLK signal clocks the digital audio data within the frames. The CODEC_BCLK signal is either an input or an output depending on whether the codec is in master or slave mode. During a playback operation, DACDAT and DACLRC must be synchronous to the CODEC_BCLK signal to avoid data corruption.
Digital Audio Data Sampling Rate
To accommodate a wide variety of commonly used DAC and ADC sampling rates, the codec allows for two modes of opera- tion, normal and USB, selected by the USB bit (Register R8, Bit D0). The sampling rate is generated as a fixed divider from the CODEC_MCLK signal. Because all audio processing references the CODEC_MCLK signal, corruption of this signal will corrupt the quality of the audio at the codec output. The ADCLRC/ ADCDAT/CODEC_BCLK or DACLRC/DACDAT/ CODEC_BCLK signals must be synchronized with CODEC_MCLK in the digital audio interface circuit. CODEC_MCLK must be faster or equal to the CODEC_BCLK frequency to guarantee that no data is lost during data synchro- nization. The CODEC_BCLK frequency should be greater than the sampling rate × word length × 2. Ensuring that the CODEC_BCLK frequency is greater than this, guarantees that all valid data bits are captured by the digital audio interface cir- cuitry. For example, if a 32 kHz digital audio sampling rate with a 32-bit word length is desired, CODEC_BCLK = 2.048 MHz. Rev. A | Page 8 of 36 | March 2010 Document Outline Blackfin Embedded Processor with Codec Processor Features Embedded Codec Features Peripherals Table of Contents Revision History General Description Codec Description ADC and DAC ADC High-Pass and DAC De-Emphasis Filters Analog Audio Interfaces Stereo Line and Monaural Microphone Inputs Bypass and Sidetone Paths to Output Line and Headphone Outputs Digital Audio Interface Recording Mode Playback Mode Digital Audio Data Sampling Rate Normal Mode USB Mode Software Control Interface Codec Pin Descriptions Register Details Bit Descriptions Specifications Operating Conditions Codec Electrical Characteristics Absolute Maximum Ratings ESD Sensitivity Package Information Power Consumption Timing Specifications TWI Timing SPI Timing Digital Audio Interface Slave Mode Timing Digital Audio Interface Master Mode Timing System Clock Timing Digital Filter Characteristics Converter Filter Response Digital De-Emphasis 289-Ball CSP_BGA Ball Assignment Outline Dimensions Ordering Guide