SDAA199 December   2025 AM620-Q1 , AM625 , AM625-Q1 , AM62A3 , AM62A3-Q1 , AM62A7 , AM62A7-Q1 , AM62P , AM62P-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Software Architecture
  6. 3 Sound Card Information
  7. 4 McASP - External Signals
  8. 5 MCASP Clock Generation and Configurations
  9. 6 Dummy Sound Card DTS Changes
  10. 7 Single DAI Link or a Single Sound Card
  11. 8 Multiple DAI Links - Single Card but Multiple Sub-Devices
  12. 9 MCASP - Practical Examples
  13. 10McASP as a Receiver
    1. 10.1 ADC or Codec as Clock Master
    2. 10.2 Device Tree Changes - Codec as Master and MCASP as Slave
  14. 11MCASP as Transmitter
    1. 11.1 Device Tree Changes - With Codec as Slave and MCASP as Master
  15. 12References

1 Introduction

One of the most useful things about McASP is its flexible clocking scheme, which allows for complete independence between the receive and transmit ports, but that flexibility means that the engineers implementing an audio system with McASP will have to make some important design choices.

The primary goal of this document is to make it easier for an engineer to determine how to connect a McASP (or multiple McASPs) to audio devices in their system.

The audio subsystem present on various TI SoCs consists of two major components:

  1. Multi-channel Audio Serial Port (McASP) - Provides a full-duplex serial interface between the host processor and external audio peripherals like codecs over industry-standard protocols like Inter-IC sound (I2S).
  2. System DMA engine - Provides McASP with direct access to system memory to read audio samples from (for playback) or store audio samples to (for capture).

Along with the above, most TI EVMs and Starter Kits have line input/output jack(s) wired to an on-board codec that can convert between the analog signals and the digital protocol supported by McASP.

Fiirst, a few disclaimers:

  • McASP is typically used to interface with devices using a time division-multiplexed (TDM) protocol, and in most cases those devices will be using a specific configuration of TDM called Inter-IC Sound (I2S). It is assumed that I2S is being used in all examples provided in this document, but that is somewhat arbitrary. The physical hookup of McASP to devices using multi-slot TDM or using I2S is the same.
  • This document is not meant to be a detailed specification. Further, this document is intended to cover McASP in general, rather than McASP on a specific TI device. It covers the key characteristics of McASP at a high level, but the device-specific Technical Reference Manual (TRM) is still the best place to go for architectural and chip-level details.