DisplayPort Audio - 2.1 English - PG199

DisplayPort 1.2 TX Subsystem LogiCORE IP Product Guide (PG199)

Document ID: PG199
Release Date: 2024-12-11
Version: 2.1 English

The DisplayPort Audio registers are listed in the following table.

Table 1. DisplayPort Audio Registers
Offset	R/W	Definition
0x300	R/W	TX_AUDIO_CONTROL. Enables audio stream packets in main link and provides buffer control. [0] Audio Enable for SST. In MST, Audio Enable for STREAM1. [1] Audio Enable for STREAM2 in MST. N/A for SST. [2] Audio Enable for STREAM3 in MST. N/A for SST. [3] Audio Enable for STREAM4 in MST. N/A for SST. 16] Set to 1 to mute the audio over link for SST. In MST, set to 1 to mute the Audio on STREAM1. [17] Set to 1 to mute the audio over link for MST STREAM2. N/A for SST. [18] Set to 1 to mute the audio over link for MST STREAM3. N/A for SST. [19] Set to 1 to mute the audio over link for MST STREAM4. N/A for SST.
0x304	R/W	TX_AUDIO_CHANNELS. Used to input active channel count. Transmitter collects audio samples based on this information. [2:0] Channel Count
0x308	WO	TX_AUDIO_INFO_DATA. [31:0] Word formatted as per CEA 861-C Info Frame. Total of eight words should be written in following order: First word – [7:0] = HB0 [15:8] = HB1 [23:16] = HB2 [31:24] = HB3 Second word – DB3,DB2,DB1,DB0 .... Eighth word – DB27,DB26,DB25,DB24 The data bytes DB1…DBN of CEA Info frame are mapped as DB0-DBN-1. No protection is provided for wrong operations by software.
0x328	R/W	TX_AUDIO_MAUD. M value of audio stream as computed by transmitter. [23:0] = Unsigned value computed when audio clock and link clock are synchronous.
0x32C	R/W	TX_AUDIO_NAUD. N value of audio stream as computed by transmitter. [23:0] = Unsigned value computed when audio clock and link clock are synchronous.
0x330 to 0x350	WO	TX_AUDIO_EXT_DATA. [31:0] = Word formatted as per Extension packet described in protocol standard. Extended packet is fixed to 32 Bytes length. The controller has buffer space for only one extended packet. Extension packet address space can be used to send the audio Copy management packet/ISRC packet/VSC packets. The TX is capable of sending any of these packets. A total of nine words should be written in following order: First word – [7:0] = HB0 [15:8] = HB1 [23:16] = HB2 [31:24] = HB3 Second word – DB3,DB2,DB1,DB0 ... Ninth word – DB31,DB30,DB29,DB28 See the DisplayPort Standard for HB* definition. No protection is provided for wrong operations by software. This is a key-hole memory, so nine writes to this address space is required.