WM9701A

Production Data

WOLFSON MICROELECTRONICS LTD.

PD Rev 3.2 January 2001

20

PR1 = 1

PR2 = 1

PR4 = 1

ADCs OFF

PR0

DACs OFF

PR1

ANALOGUE

OFF PR2

OR PR3

DIGITAL I/F

OFF PR4

WARM RESET

PR1 = 0 AND

DAC = 1

PR2 = 0 AND

ANL = 1

SHUT OFF

CODA LINK

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.