Audio Packet Type Flags - Analog Devices ADV7850 Hardware Manual

Function
audio_fifo_almost_full_
threshold[6:0]
1111101 

7.27 AUDIO PACKET TYPE FLAGS

The ADV7850 can receive and process four types of audio packet:
•
Audio sample packets
• DSD packets
•
DST packets
• HBR packets
The following flags are provided to monitor the type of audio packets received by the ADV7850.
be implemented to monitor the type of audio packet processed by the ADV7850.
audio_mode_chng_raw, IO, Address 0x83[5] (Read Only)
This readback indicates the status of the audio mode change interrupt signal. When set to 1, it indicates that the type of audio packet
received has changed. The following are considered audio modes; no audio packets, Audio Sample Packet, DSD packet, HBR Packet or
DST Packet. Once set, this bit will remain high until it is cleared via audio_mode_chng_clr.
Function
audio_mode_chng_raw
0 
1
audio_sample_pckt_det, Addr 68 (HDMI), Address 0x18[0] (Read Only)
This control is used to detect an audio sample packet. It resets to 0 on the 11th HSync leading edge following an audio packet if a
subsequent audio sample packet is not received or if a DSD, DST or HBR audio packet sample packet was received.
Function
audio_sample_pckt_det
0 
1
dsd_packet_det, Addr 68 (HDMI), Address 0x18[1] (Read Only)
This control is used to detect a DSD audio packet. It resets to 0 on the 11th HSync leading edge following a DSD packet or if an audio,
DST or HBR packet sample packet was received or after an HDMI reset condition.
Function
dsd_packet_det
0 
1
hbr_audio_pckt_det, Addr 68 (HDMI), Address 0x18[3] (Read Only)
This control is used to detect an HBR packet. It resets to 0 on the 11th HSync leading edge following an HBR packet if a subsequent
HBR packet is not detected. It also resets if an audio, DSD or DST packet sample packet is received, or after an HDMI reset condition.
Rev. A May 2012
Description
Default
Description
Audio mode not changed.
Audio mode changed.
Description
No l_pcm or IEC 61937 compressed audio sample packet received within last 10 HSyncs
l_pcm or IEC 61937 compressed audio sample packet received within last 10 HSync
Description
No DSD packet received within last 10 HSync
DSD packet received within last 10 HSync
181
Figure 63 shows the algorithm that can
ADV7850