Audio Fifo - Analog Devices ADV7610 Hardware User's Manual

UG-438

AUDIO FIFO

The audio FIFO can store up to 128 audio stereo data from the audio sample or DST packets. Stereo audio data are added into the FIFO
from the audio packet received. Stereo audio data are retrieved from the FIFO at a rate corresponding to 128 times the audio sampling
frequency, f .
s
The status of the audio FIFO can be monitored through the status flags FIFO_UNDERFLO_RAW, FIFO_OVERFLO_RAW,
FIFO_NEAR_OVFL_RAW, and FIFO_NEAR_UFLO_RAW.
FIFO_UNDERFLO_RAW, IO, Address 0x7E[6] (Read Only)
Status of audio FIFO underflow interrupt signal. When set to 1, it indicates the audio FIFO read pointer has reached the write pointer
causing the audio FIFO to underflow. Once set, this bit will remain high until it is cleared via AUDIO_FIFO_UNDERFLO_CLR.
Function
FIFO_UNDERFLO_RAW
0 (default)
1
FIFO_OVERFLO_RAW, IO, Address 0x7E[5] (Read Only)
Status of audio FIFO overflow interrupt signal. When set to 1, it indicates audio FIFO write pointer has reached the read pointer causing
the audio FIFO to overflow. Once set, this bit will remain high until it is cleared via AUDIO_FIFO_OVERFLO_CLR.
Function
FIFO_OVERFLO_RAW
0 (default)
1
FIFO_NEAR_UFLO_RAW, IO, Address 0x83[0] (Read Only)
Status of audio FIFO near underflow interrupt signal. When set to 1, it indicates the audio FIFO is near underflow as the number of FIFO
registers containing stereo data is less or equal to value set in AUDIO_FIFO_ALMOST_EMPTY_THRESHOLD. Once set, this bit will
remain high until it is cleared via FIFO_NEAR_UFLO_CLR.
Function
FIFO_NEAR_UFLO_RAW
0 (default)
1
ADDRESS ORDER
EMPTY
...
...
...
EMPTY
STEREO DATA N – 1
STEREO DATA N – 2
...
...
...
STEREO DATA 1
STEREO DATA 0
EMPTY
EMPTY
Description
Audio FIFO has not underflowed.
Audio FIFO has underflowed.
Description
Audio FIFO has not overflowed.
Audio FIFO has overflowed.
Description
Audio FIFO has not reached low threshold defined in AUDIO_FIFO_ALMOST_EMPTY_THRESHOLD [5:0].
Audio FIFO has reached low threshold defined in AUDIO_FIFO_ALMOST_EMPTY_THRESHOLD [5:0].
ADDRESS 63
WRITE POINTER
ADDRESS N + 2
ADDRESS N + 1
ADDRESS N
ADDRESS 3
READ POINTER
ADDRESS 2
ADDRESS 1
ADDRESS 0
Figure 12. Audio FIFO
Rev. 0 | Page 48 of 184
Hardware User Guide