Codec Reset - Samsung S3C2416 User Manual

AC97 CONTROLLER S3C2416X RISC MICROPROCESSOR

6 CODEC RESET

For details, please refer the CODEC Reset part of AC97 revision 2.0 specification.
6.1.1 Cold AC97 Reset
A cold reset is generated when the nRESET pin is asserted through the AC_GLBCTRL. Asserting and
deasserting nRESET activates BITCLK and SDATA_OUT. All AC97 control registers are initialized to their default
power on reset values. nRESET is an asynchronous AC97 input.
6.1.2 Warm AC97 Reset
A Warm AC97 reset reactivates the AC-link without altering the current AC97 register values. A warm reset is
generated when BITCLK is absent and SYNC is driven high. In normal audio frames, SYNC is a synchronous
AC97 input. When BITCLK is absent, SYNC is treated as an asynchronous input used to generate a warm reset
to AC97.The AC97 Controller must not activate BITCLK until it samples SYNC low again. This prevents a new
audio frame from being falsely detected.
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