Audio Clock Regeneration Parameters; Acr Parameters Readbacks; Monitoring Acr Parameters - Analog Devices ADV7850 Hardware Manual

Function
mt_msk_parity_err
1 

7.32 AUDIO CLOCK REGENERATION PARAMETERS

The ADV7850 recreates an internal audio master clock using Audio Clock Regeneration (ACR) values transmitted by the HDMI source.

ACR Parameters Readbacks

7.32.1
The registers N and CTS can be read back from the HDMI Map.
cts[19:0], Addr 68 (HDMI), Address 0x5B[7:0]; Address 0x5C[7:0]; Address 0x5D[7:4] (Read Only)
This readback indicates the CTS value received in the HDMI datastream.
Function
cts[19:0]
00000000000000000000

xxxxxxxxxxxxxxxxxxxx
n[19:0], Addr 68 (HDMI), Address 0x5D[3:0]; Address 0x5E[7:0]; Address 0x5F[7:0] (Read Only)
This readback indicates the N value received in the HDMI datastream.
Function
n[19:0]
00000000000000000000

xxxxxxxxxxxxxxxxxxxx
Note: A buffer has been implemented for the N and CTS readback registers. A read of the HDMI Map, Address 0x5B register updates the
buffer that stores the N and CTS readback registers. The buffer implemented for N and CTS readback allows the reading of both N and
CTS registers within an I C block read.
2

Monitoring ACR Parameters

7.32.2
The reception of ACR packets can be notified via audio_c_pckt_raw. Changes in N and CTS can be monitored via
cts_pass_thrsh_raw, as described in this section.
audio_c_pckt_raw, IO, Address 0x65[1] (Read Only)
This readback indicates the raw status signal of the audio clock regeneration packet detection signal.
Function
audio_c_pckt_raw
0 
1
change_n_raw, IO, Address 0x7E[3] (Read Only)
This readback indicates the status of the ACR N value changed interrupt signal. Once set to 1, it indicates the N value of the ACR
packets has changed. Once set, this bit remains high until it is cleared via change_n_clr.
Rev. A May 2012
Description
Audio mute occurs if audio sample packet is received with incorrect parity bit.
Description
Default CTS value readback from HDMI stream
CTS value readback from HDMI stream
Description
Default N value readback from HDMI stream
N value readback from HDMI stream
Description
No audio clock regeneration packets received since last HDMI reset condition
Audio clock regeneration packets received
195
ADV7850
change_n_raw and