ANALOG DEVICES ADAU1442, ADAU1445, ADAU1446 Service Manual

SigmaDSP Digital Audio Processor with

Silicon Anomaly

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.

Flexible Audio Routing Matrix

ADAU1442/ADAU1445/ADAU1446

ADAU1442/ADAU1445/ADAU1446 FUNCTIONALITY ISSUES

Silicon Status Anomaly Sheet No. of Reported Anomalies

Release Rev. 0 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 I

None.

S-to-S/PDIF transceiver IC.

SECTION 1. ADAU1442/ADAU1445/FUNCTIONALITY ISSUES

Reference Number Description Status

er001 S/PDIF transmitter validity bit setting Open

Rev. 0

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ADAU1442/ADAU1445/ADAU1446 Silicon Anomaly

NOTES

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