wm9703 ETC-unknow, wm9703 Datasheet - Page 24

• Manufacturer Part Number: wm9703
• Manufacturer: ETC-unknow

WM9703
POWERDOWN CONTROL/STATUS REGISTER (INDEX 26h)
WOLFSON MICROELECTRONICS LTD
RESERVED REGISTER (INDEX 24h)
This register was originally specified to control what sample rate AC’97 is sending or receiving
samples for the optional modem in and out. Not supported by the WM9703.
This read/write register is used to program powerdown states and monitor subsystem readiness. The
lower half of this register is read only status, a 1 indicating that the subsection is ready. Ready is
defined as the subsection able to perform in its nominal state. When this register is written the bit
values that come in on AC-link will have no effect on read only bits 0 to7.
When the AC-link Codec Ready indicator bit (SDATA_IN slot 0, bit 15) is a 1 it indicates that the AC-
link and the WM9703 control and status registers are in a fully operational state. The AC’97 controller
must further probe this Powerdown Control/Status Register to determine exactly which subsections,
if any, are ready.
Table 16 Powerdown Status Register Function
The powerdown modes are as follows. The first three bits are to be used individually rather than in
combination with each other. The last bit PR3 can be used in combination with PR2 or by itself. PR0
and PR1 control the PCM ADCs and DACs only. PR6 is not supported by the WM9703.
Table 17 Powerdown Control Register Function
Figure 17 An Example of the WM9703 Powerdown/Powerup Flow
PR0
PR1
PR2
PR3
PR4
PR5
PR6
EAPD
WRITE BIT
READ BIT
DAC
ADC
REF
ANL
NORMAL
PR0 = 0 AND
ADC = 1
PR0 = 1
FUNCTION
VREFs up to nominal level
Analogue mixers, etc ready
DAC section ready to accept data
ADC section ready to transmit data
FUNCTION
PCM in ADCs and input Mux powerdown
PCM out DACs powerdown
Analogue mixer powerdown
(VREF still on)
Analogue mixer powerdown (VREF off)
Digital interface (AC-link) powerdown
(external clock off)
Internal clock disable
HP amp powerdown – not supported
External amplifier powerdown
READY = 1
ADCs OFF
PR0
PR1 = 0 AND
DAC = 1
PR1 = 1
DACs OFF
PR1
PR2 = 0 AND
ANL = 1
DEFAULT
PR2 = 1
OFF PR2 OR
ANALOGUE
PR3
PR4 = 1
COLD RESET
DIGITAL I/F
OFF PR4
RESET
WARM
PD Rev 3.4 January 2001
Production Data
CODA LINK
SHUT OFF
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