Audio Clock Regeneration Parameters - Analog Devices Advantiv ADV7619 Hardware User's Manual

UG-237
Function
MT_MSK_PARITY_ERR
1 (default)

AUDIO CLOCK REGENERATION PARAMETERS

The ADV7619 recreates an internal audio master clock using audio clock regeneration (ACR) values transmitted by the HDMI source.
ACR Parameters Readbacks
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)
A readback for the CTS value received in the HDMI data stream.
Function
CTS[19:0]
00000000000000000000 (default)
xxxxxxxxxxxxxxxxxxxx
N[19:0] , Addr 68 (HDMI), Address 0x5D[3:0]; Address 0x5E[7:0]; Address 0x5F[7:0] (Read Only)
A readback for the N value received in the HDMI data stream.
Function
N[19:0]
00000000000000000000 (default)
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
2
CTS registers within an I C block read.
Monitoring ACR Parameters
The reception of ACR packets can be notified via the AUDIO_C_PCKT_RAW flag. Changes in N and CTS can be monitored via the
CHANGE_N_RAW and CTS_PASS_THRSH_RAW flags, as described in this section.
AUDIO_C_PCKT_RAW , IO, Address 0x65[1] (Read Only)
Raw status signal of audio clock regeneration packet detection signal.
Function
AUDIO_C_PCKT_RAW
0 (default)
1
CHANGE_N_RAW , IO, Address 0x7E[3] (Read Only)
Status of the ACR N Value changed interrupt signal. When set to 1 it indicates the N Value of the ACR packets has changed. Once set, this
bit will remain high until it is cleared via CHANGE_N_CLR.
Function
CHANGE_N_RAW
0 (default)
1
CTS_PASS_THRSH_RAW , IO, Address 0x7E[4] (Read Only)
Status of the ACR CTS value exceed threshold interrupt signal. When set to 1, it indicates the CTS Value of the ACR packets has exceeded
the threshold set by CTS_CHANGE_THRESHOLD. Once set, this bit will remain high until it is cleared via CTS_PASS_THRSH_CLR.
Function
CTS_PASS_THRSH_RAW
0 (default)
1
Description
Audio mute occurs if an audio sample packet is received with an 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 the last HDMI reset condition
Audio clock regeneration packets received
Description
Audio clock regeneration N value has not changed.
Audio clock regeneration N value has changed.
Description
Audio clock regeneration CTS value has not passed the threshold.
Audio clock regeneration CTS value has changed more than threshold.
Rev. A | Page 76 of 204
Hardware User Guide