Audio Input Stream Interface - 3.2 English

HDMI 1.4/2.0 Transmitter Subsystem Product Guide (PG235)

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3.2 English

The following table shows the signals for AXI4-Stream audio streaming interfaces. The audio interface transports 24-bits L-PCM or 16-bits HBR audio samples in the IEC 60958 format. A maximum of 32 channels are supported. The audio interface is a 32-bit AXI4-Stream slave interface and runs at the s_axis_audio_aclk clock rate.

Table 1. Audio Input Stream Interface
Name I/O Width Description
s_axis_audio_aclk I 1 Clock (The audio streaming clock must be greater than or equal or greater than 128 times the audio sample frequency)
s_axis_audio_aresetn I 1 Reset (Active-Low)
AUDIO_IN_tdata I 32 Data
  • [31] P (Parity)
  • [30] C (Channel status)
  • [29] U (User bit)
  • [28] V (Validity bit)
  • [27:4] Audio sample word for L-PCM/3D-Audio
  • [27:12] Audio sample word for HBR
  • [3:0] Preamble code
  • 4'b0001 Subframe 1/Left Channel and start of audio block
  • 4'b0010 Subframe 1/Left Channel
  • 4'b0011 Subframe 2/Right Channel
AUDIO_IN_tid I 8 Channel ID
AUDIO_IN_tready O 1 Ready
AUDIO_IN_tvalid I 1 Valid
Note: The L-PCM (Packet Type 0x02 and 0x0B) allows you to pack up to 24 bits of audio from the Audio Data Stream. The HBR (Packet Type 0x09) allows you to pack up to 16 bits of audio from the Audio Data Stream. The data is taken from MSB (bit 27:12). Compressed Audio (IEC 61937) can also be sent the same as L-PCM data (IEC60958). However, it is your responsibility to compress the audio data with your custom logic.