Samsung S3C6400X User Manual page 1070

AC97 CONTROLLER
PR0 = 1
Normal
PR0 = 0
&
ADC = 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.
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.
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
35-10
Specifications and information herein are subject to change without notice.
PR1 = 1
ADCs off DACs off
PR0 PR1
PR1 = 0
&
DAC = 1
Ready = 1
Figure 35-8 AC97 Power down/Power up Flow
PR2 = 1 PR4 = 1
Analog
off
PR2 or
PR3
PR2 = 0
&
ANL = 1
Default
S3C6400 RISC MICROPROCESSOR
Digitial I/F
Shut off
off
AC-link
PR4
Warm Reset
Cold Reset