Silicon Anomaly SigmaDSP Digital Audio Processor with
Flexible Audio Routing Matrix
ADAU1442/ADAU1445/ADAU1446 This anomaly list describes the known bugs, anomalies, and workarounds for the ADAU1442/ADAU1445/ADAU1446.
Analog Devices, Inc., is committed, through future silicon revisions, to continuously improving silicon functionality. Analog Devices tries
to ensure that these future silicon revisions remain compatible with your present software/systems by implementing the recommended
workarounds outlined here. ADAU1442/ADAU1445/ADAU1446 FUNCTIONALITY ISSUES
Silicon Status
Release Anomaly Sheet
Rev. 0 No. of Reported Anomalies
1 FUNCTIONALITY ISSUES
Table 1. S/PDIF Transmitter Validity Bit Setting [er001]
Background Issue Workaround Related Issues The S/PDIF transmitter outputs two channels of audio data directly from the DSP core at the core rate. It does not
preserve or output any additional nonaudio information encoded in the S/PDIF input stream, such as the validity
bit, user data, and channel status. The encoded nonaudio data bits in the S/PDIF output stream are hardwired
internally to logic low values, except for the validity bit, which is set as logic high.
In the S/PDIF specification, a high validity bit indicates invalid data. For this reason, if the output from the
ADAU1442/ADAU1445/ADAU1446 SPDIFO pin is connected directly to an S/PDIF receiver IC, the receiver may
ignore or discard the transmitted audio data because the high validity bit indicates an error. Alternatively, some
S/PDIF receivers (including the ADAU1442/ADAU1445/ADAU1446 SPDIFI pin) may ignore the validity bit and
pass the data through.
This issue cannot be avoided because the validity bit value is internally hardcoded. If an S/PDIF output is
required in the system, audio data can instead be routed to the ADAU1442/ADAU1445/ADAU1446 serial ports
and then to an I2S-to-S/PDIF transceiver IC. …