Msa interface, Msa interface -22 – Altera DisplayPort MegaCore Function User Manual

Page 58

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Figure 5-10: rxN_audio Data Output

Audio Sample Period

rxN_audio_lpcm_data

rx_ss_clk

rxN_audio_valid

The captured audio infoframe is available on the audio port. The 5-byte port corresponds to the 5 bytes

used in the audio infoframe (refer to CEA-861-D). The audio infoframe describes the type of audio

content.

MSA Interface

The

rxN_msa_conduit

ports allow designs access to the MSA and VB-ID parameters on a top-level port.

The following table shows the 217-bit port bundle assignments. The prefixes

msa

and

vbid

denote

parameters from the MSA and Vertical Blank ID (VB-ID) packets, respectively.
The sink asserts bit

msa_valid

when all

msa_

signals are valid and deasserts during MSA update. The sink

assigns the MSA parameters to zero when it is not receiving valid video data.
The sink asserts the

msa_lock

bit when the MSA fields have been correctly formatted for the last 15 video

frames. Because

msa_lock

changes state only when

msa_valid

= 1, you can use its rising edge to strobe

new MSA values following an idle video period; for example, when the source changes video resolution.

You can use its deasserted state to invalidate received video data.
The sink asserts bit

vbid_strobe

for one clock cycle when it detects the VB-ID and all

vbid_

signals are

valid to be read.

Table 5-14: rxN_msa_conduit Port Signals

Bit

Signal

Comments

216

msa_lock

0 = MSA fields format error. 1 = MSA fields correctly

formatted.

215

vbid_strobe

0 = VB-ID fields invalid, 1 = VB-ID fields valid.

5-22

MSA Interface

UG-01131

2015.05.04

Altera Corporation

DisplayPort Sink

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