HDMI Intel® FPGA IP User Guide

ID 683798
Date 12/04/2023
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5.1.8.1. Audio InfoFrame (AI) Bundle Bit-Fields

The core sends the AI default values in the auxiliary packets.

The default values are overridden by the customized input values (audio_info_ai[47:0]) when the input checksum is non-zero. The core sends the AI packet on the active edge of the V-SYNC signal to ensure that the packet is sent once per field.

Table 28.  Source Audio InfoFrame Bundle Bit-Fields

The following table lists the AI signal bit-fields (as described in HDMI 1.4b Specification Section 8.2.2). The signal bundle is clocked by ls_clk for Support FRL = 0 designs and by vid_clk for Support FRL = 1 designs.

Bit-field Name Description Default Value
7:0 Checksum Checksum 8’h71
10:8 CC Channel count 3’h0
11 Reserved Returns 0 1’h0
15:12 CT Audio format type 4’h0
17:16 SS Bits per audio sample 2’h0
20:18 SF Sampling frequency 3’h0
23:21 Reserved Returns 0 3’h0
31:24 CXT Audio format type of the audio stream 8’h00
39:32 CA Speaker location allocation FL, FR 8’h00
41:40 LFEPBL LFE playback level information, dB 2’h0
42 Reserved Returns 0 1’h0
46:43 LSV Level shift information, dB 4’h0
47 DM_INH Down-mix inhibit flag 1’h0
48 Control Disables the core from inserting the AI packet.
  • 1: The core does not insert audio_info_ai[47:0]. The AI packet on the Auxiliary Data Port passes through.
  • 0: The core inserts audio_info_ai[47:0] when there is a non-zero bit. The core sends default values when all bits are zero. The core filters the AI packet on the Auxiliary Data Port.