AK4541VQ Asahi Kasei Microsystems, AK4541VQ Datasheet - Page 23

• Manufacturer Part Number: AK4541VQ
• Description: AC97 Rev 2.1 Multimedia Audio CODEC
• Manufacturer: Asahi Kasei Microsystems

[ASAHI KASEI]
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The AK4541 is capable of operating at multiple reduced power modes for when no activity is required. The state of power down is
controlled by the Powerdown Register (26h). There are 8 separate commands for power down. See the table below for the different
modes. As the AK4541 operates at static mode, the registers will not lose their values even if the master clock is stopped only upon
power.
Powerdown Mode Truth Table
*: PD means Powerdown .
*: No DAC out means that there is no PCM out because mixer is disabled.
From normal operation sequential writes to the Powerdown Register are performed to power down subsections of the AK4541 one at
a time. After everything has been shut off, a final write (of PR4) can be executed to shut down the AC ’97 digital interface (AC-link).
The part will remain in sleep mode with all its registers holding their static values. To wake up, the AC ‘97 controller will send a pulse
on the sync line issuing a warm reset. This will restart the AK4541 digital (resetting PR4 to zero). The AK4541 can also be woken up
with a cold reset. A cold reset will cause a loss of values of the registers as a cold reset will set them to their default states. When a
subsection is powered back on the Powerdown Control/Status register (index 26h) should be read to verify that the section is ready
(i.e. stable) before attempting any operation that requires its normal operation.
<M0047-E-01>
PR0=”1”
PR1=”1”
PR2=”1”
PR3=”1”
PR4=”1”
PR5=”1”
PR6=”1”
PR7=”1”
don’t care
don’t care
don’t care
don’t care
Normal
ADC
PD
PD
PD
PD
PR0=1
ADC=1
PR0=0
Ready = 1
&
(No DAC out)
don’t care
don’t care
don’t care
don’t care
DAC
ADCs off
PD
PD
PD
PD
PR0
PR1=1
DAC=1
PR1=0
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
&
Mixer
PD
PD
DACs off
PR1
Default
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
PR2=1
VREF
PR2=0
ANL=1
PD
- 23 -
&
PR2 or
Analog
PR3
off
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
Don’t care
ACLINK
PD
PD
PR4=1
Warm Reset
Cold Reset
Internal CLK
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
Digital I/F
PR4
PD
off
LNLVL_OUT
don’t care
don’t care
don’t care
don’t care
don’t care
PD
PD
PD
AC-Link
Shut off
[AK4541]
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
don’t care
1999/01
EAPD
PD