WM9701 Wolfson Microelectronics plc, WM9701 Datasheet - Page 20

• Manufacturer Part Number: WM9701
• Description: Low Power AC97 Multimedia Audio Codec
• Manufacturer: Wolfson Microelectronics plc

WM9701A
WOLFSON MICROELECTRONICS LTD.
Figure 13 WM9701A Power Down/Flow with Analogue Still Alive
Figure 13 illustrates a state when all the mixers should work with the static volume settings that are
contained in their associated registers. This is used when the user could be playing a CD (or
external LINE_IN source) through WM9701A to the speakers but have most of the system in low
power mode. The procedure for this follows the previous except that the analogue mixer is never
shut down.
POWERDOWN CONTROL/STATUS REGISTER (INDEX 26H)
Also when RESETB pin is asserted low, all PR bits are over-ridden and the entire device is powered
off to ultra low power state for as long as RESETB = low. On releasing RESETB, the device is reset
(all active) and powered up.
RESERVED REGISTERS (INDEX 28h - 58h)
These registers are reserved by AC’97 and have no function on WM9701A.
VENDOR RESERVED REGISTERS (INDEX 5AH - 7Ah)
These are reserved for future use and are vendor specific. Do not write to these registers unless the
Vendor ID register has been checked first to ensure that the driver knows the source of the AC’97
component. Values stored in this register are used to provide test modes for the manufacturer.
VENDOR SPECIFIC GAIN CONTROL REGISTERS – (INDEX 70H TO 74H)
Not used in the WM9701A.
VENDOR ID REGISTERS (INDEX 7Ch - 7Eh)
This register is for specific vendor identification if so desired. The ID method is Microsoft’s Plug and
Play Vendor ID code. The first character of that ID is F7 to F0, the second character S7 to S0 and
the third T7 to T0. These three characters are ASCII encoded. The REV7 to REV0 field is for the
Vendor Revision number. In WM9701A the vendor ID is set to WML0.
Wolfson is a registered Microsoft Plug and Play vendor.
ADCs OFF
PR0
PR1 = 0 AND
DAC = 1
PR1 = 1
DACs OFF
PR1
PR2 = 0 AND
PR2 = 1
ANL = 1
ANALOGUE
OFF PR2
OR PR3
PR4 = 1
WARM RESET
DIGITAL I/F
OFF PR4
PD Rev 3.2 January 2001
CODA LINK
Production Data
SHUT OFF
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