Cirrus Logic CobraNet Audio Routing Primer - Manual (Page 4)

Example:
We have two standard CM-2 modules to be configured as a transmitter and a receiver. We want to send
the audio data with standard latency, a 48-kHz sample rate and 20 bit sample size.
We would like to send two audio channels from the transmitter to the receiver in one unicast bundle.
Bundle number 273 is a valid unicast bundle number suitable for use.
SSI interface 1 is connected to a 2 channel A to D on the transmitter and SSI interface 1 is connected to a
2 channel D to A on the receiver.
For the transmitting interface the following values should be set:
txBundle 273 Assign bundle number to transmitter
txSubCount >= 2 Make sure bundle is big enough
txSubMap.1 1 Assign audio routing channel to 1 st bundle channel
txSubMap.2 2 Assign audio routing channel to 2 nd bundle channel
txSubFormat.1 0x54000 Set format of 1 st audio channel
txSubFormat.2 0x54000 Set format of 2 nd audio channel
modeRateControl 0x600 Set interface latency and sample rate
For the receiving interface the following values should be set:
rxBundle 273 Assign bundle number to receiver
rxSubMap.1 33 Assign 1 st bundle channel to audio routing channel
rxSubMap.2 34 Assign 2 nd bundle channel to audio routing channel
modeRateControl 0x600 Set interface latency and sample rate
Once the variables are properly set, the CobraNet TM protocol takes over to make sure the Bundles (audio
data) go to and from the correct interfaces. The reservation and reverse reservation components of the
CobraNet
TM protocol, which are transparent to the user, automatically detect when a transmitter and one or
more receivers on the network have the same bundle numbers assigned. It will then establish the connection
between these interfaces via the permissions component of the protocol, again transparent to the user, and
cause bundles to flow from the transmitting interface to one or more receiving interfaces with the same
bundle number assignment(s).
Refer to the Programmer’s Reference for detailed information about addressing these variables via HMI or
SNMP.
Additional Information
Refer to the Cirrus Logic Application Note “Bundle Assignments In CobraNet TM Systems” for further
information on the use of bundles and their implications on network design and utilization.
CobraNet TM Audio Routing Primer Rev. 1.2 ©Copyright 2004 Cirrus Logic, Inc
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