Cirrus Logic CobraNet - Manual (Page 23)

CobraNet Programmer’s Reference
Audio Paths
DS651PM25
©
Copyright 2006 Cirrus Logic, Inc. 23
A CobraNet interface operates at a single latency and sample rate mode as specified by
the
modeRateControl variable. This latency mode applies to all incoming and outgoing
audio at the interface.
1 rxSubFormat is a read only variable indicating the format of the audio data being
received and decoded. It will have the same value as
txSubFormat with the exception of
the least-significant bit. i.e. 16-bit, 48 kHz sample rate, 5 1/3-mS latency = 0x44001 when
the data is being successfully decoded.
2 modeRateControl must also be set to the correct value necessary to support the mode
selected by txSubFormat.
4.8 96 kHz Sample Rate Support
A CobraNet interface may operate at either 48 kHz or 96 kHz but not both rates
simultaneously. A device operating at 48 kHz cannot receive audio from a device
operating at 96 kHz and vice versa. However, CobraNet interfaces operating at 96 kHz
and 48 kHz audio may co-exist on the same network.
CS4961xx, CS1810xx, CM-2, and CM-1 based interfaces are required for 96 kHz sample
rate operation. No hardware changes are required to support the increased sample rate
on these platforms. 96 kHz is not supported in the legacy CobraNet Reference Design.
Table 6. txSubFormat and rxSubFormat 1
Values
2
txSubFormat Value Resolution Sample Rate Latency
0 No Signal
0x044000 16 bit 48 kHz 5-1/3 ms
0x054000 20 bit 48 kHz 5-1/3 ms
0x064000 24 bit 48 kHz 5-1/3 ms
0x148000 16 bit 96 kHz 5-1/3 ms
0x158000 20 bit 96 kHz 5-1/3 ms
0x168000 24 bit 96 kHz 5-1/3 ms
0x042000 16 bit 48 kHz 2-2/3 ms
0x052000 20 bit 48 kHz 2-2/3 ms
0x062000 24 bit 48 kHz 2-2/3 ms
0x144000 16 bit 96 kHz 2-2/3 ms
0x154000 20 bit 96 kHz 2-2/3 ms
0x164000 24 bit 96 kHz 2-2/3 ms
0x041000 16 bit 48 kHz 1-1/3 ms
0x051000 20 bit 48 kHz 1-1/3 ms
0x061000 24 bit 48 kHz 1-1/3 ms
0x142000 16 bit 96 kHz 1-1/3 ms
0x152000 20 bit 96 kHz 1-1/3 ms
0x162000 24 bit 96 kHz 1-1/3 ms