Product Preview
WM8802
DESCRIPTION OF MODULATION FUNCTION AND GENERAL-PURPOSE I/OS
MODULATION FUNCTION USAGE METHOD
INITIAL SETTING
The modulation function and general-purpose I/O port function cannot be used simultaneously
because they share the same pins. INT should be pulled down with a 10kΩ resistor to select the
modulation function. For the setting method, see page 10.
In the initial setting, the modulation function is stopped. The modulation function can be set using
TXOPR.
DATA OUTPUT (TMCK, TBCK, TLRCK, TDATA, TXO)
Bi-phase modulated data is output from TXO by inputting a 256fs clock to TMCK, 64fs clock to
TBCK, fs clock to TLRCK and audio data to TDATA.
The polarity of the TLRCK clock is set using TXLRP.
Input data can be modulated in the sampling range of 32kHz to 192kHz, TMCK rate of 4MHz to
25MHz and up to 24 bit data.
The initial value for the input data format is I2S. Switching to Left Justified format is set using TXDFS.
For the channel status, the first 48 bits of data can be written with the micro-controller interface.
TXO is fixed to Low by setting TXOPR to Stop.
1/fs
LEFT
RIGHT
CHANNEL
CHANNEL
TLRCK (I)
TBCK (I)
1 BCLK
1 BCLK
TDATA (I)
1
2
3
n
1
2
3
n
n-2 n-1
n-2 n-1
LSB
LSB
MSB
MSB
16 to 24 bits
16 to 24 bits
Figure 25 Data Input Timing – I2S Data Input
PP Rev 1.1 April 2004
33
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
