wm9715l Wolfson Microelectronics plc, wm9715l Datasheet - Page 54

• Manufacturer Part Number: wm9715l
• Description: Ac?97 Audio And Touchpanel Codec
• Manufacturer: Wolfson Microelectronics plc

WM9715L
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POWER MANAGEMENT
The WM9715L includes the standard power down control register defined by the AC’97 specification
(register 26h). Additionally, it also allows more specific control over the individual blocks of the device
through register 24h. Each particular circuit block is active when both the relevant bit in register 26h
AND the relevant bit in register 24h are set to ‘0’.
Table 39 Powerdown and Status Register (Conforms to AC’97 Rev 2.2)
POWER-UP
As can be seen from the table above, most blocks are ‘ON’ by default. However, if the PWRUP pin is
held high during reset, the WM9715L starts up with all blocks powered down, saving power. This is
achieved by connecting a pull-up resistor (e.g. 100kΩ) from PWRUP to DBVDD. Note that the state
of PWRUP during reset only affects register 26h.
26h
Powerdown/
Status
register
REGISTER
ADDRESS
BIT
14
13
12
11
10
9
8
3
2
1
0
LABEL
DAC
ADC
PR6
PR5
PR4
PR3
PR2
PR1
PR0
REF
ANL
NORMAL
0 (ON)
0 (ON)
0 (ON)
0 (ON)
0 (ON)
0 (ON)
0 (ON)
1
1
1
1
DEFAULT
‘HI’ DURING
PWRUP PIN
1 (OFF)
1 (OFF)
1 (OFF)
1 (OFF)
1 (OFF)
1 (OFF)
1 (OFF)
RESET
0
0
0
0
Disables HPOUTL, HPOUTR and
OUT3 Buffer
Disables internal clock
Disables AC-link interface
(external clock off)
Disables VREF, analogue mixers
and outputs
Disables analogue mixers,
LOUT2, ROUT2 (but not VREF)
Disables stereo DAC
Disables audio ADCs and input
Mux
Read-only bit, indicates VREF is
ready (inverse of PR2)
Read-only bit, indicates analogue
mixers are ready (inverse of PR3)
Read-only bit, indicates audio
DACs are ready (inverse of PR1)
Read-only bit, indicates audio
ADCs are ready (inverse of PR0)
PD Rev 4.0 December 2007
DESCRIPTION
Production Data
54