WM8731L WOLFSON [Wolfson Microelectronics plc], WM8731L Datasheet - Page 46

• Manufacturer Part Number: WM8731L
• Description: Portable Internet Audio CODEC with Headphone Driver and Programmable Sample Rates
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM8731 / WM8731L
POWER DOWN MODES
w
Once the WM8731/L has acknowledged a correct address, the controller will send eight data bits
(bits B15-B8). WM8731/L will then acknowledge the sent data by pulling SDIN low for one clock
pulse. The controller will then send the remaining eight data bits (bits B7-B0) and the WM8731/L will
then acknowledge again by pulling SDIN low.
A stop condition is defined when there is a low to high transition on SDIN while SCLK is high. If a
start or stop condition is detected out of sequence at any point in the data transfer then the device
will jump to the idle condition.
After receiving a complete address and data sequence the WM8731/L returns to the idle state and
waits for another start condition. Each write to a register requires the complete sequence of start
condition, device address and R/W bit followed by the 16 register address and data bits.
The WM8731/L contains power conservation modes in which various circuit blocks may be safely
powered down in order to conserve power. This is software programmable as shown in the table
below.
Table 26 Power Conservation Modes Software Control
The power down control can be used to either a) permanently disable functions when not required in
certain applications or b) to dynamically power up and down functions depending on the operating
mode, e.g.: during playback or record. Please follow the special instructions below if dynamic
implementations are being used.
LINEINPD: Simultaneously powers down both the Line Inputs. This can be done dynamically without
any audible effects either on the ADC or to the Line Outputs in Bypass mode. This is of use when the
device enters Playback, Pause or Stop modes or the Microphone input has been selected.
0000110
Power Down
Control
REGISTER
ADDRESS
0
1
2
3
4
5
6
7
BIT
LINEINPD
MICPD
ADCPD
DACPD
OUTPD
OSCPD
CLKOUTPD
POWEROFF
LABEL
DEFAULT
1
1
1
1
1
0
0
1
Line Input Power Down
1 = Enable Power Down
0 = Disable Power Down
Microphone Input an Bias
Power Down
1 = Enable Power Down
0 = Disable Power Down
ADC Power Down
1 = Enable Power Down
0 = Disable Power Down
DAC Power Down
1 = Enable Power Down
0 = Disable Power Down
Line Output Power Down
1 = Enable Power Down
0 = Disable Power Down
Oscillator Power Down
1 = Enable Power Down
0 = Disable Power Down
CLKOUT power down
1 = Enable Power Down
0 = Disable Power Down
Power Off Device
1 = Device Power Off
0 = Device Power On
DESCRIPTION
PD Rev 4.3 August 2006
Production Data
46