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WM8802
CHIP ADDRESS SETTINGS (EMPHA/UO, AUDIO /VO)
The WM8802 comes with a function to set a unique chip address to allow the use of several
WM8802 on the same micro-controller bus.
A 10kΩ pull-down or pull-up resistor is used to set EMPHA/UO and AUDIO /VO as the chip address
settings. This allows up to set 4 chip addresses.
Chip addresses in the micro-controller interface can be set with CAL and CAU provided that they are
first two bits on the LSB side. CAL and CAU corresponds to the lower and higher chip address
respectively.
Address writing to a particular device is enabled by making the chip address setting, using
EMPHA/UO and AUDIO /VO, the same as the chip addresses sent from the micro-controller.
The chip address setting must be performed even when using only one WM8802 in the system. The
chip address is undefined and control from the micro-controller cannot be performed if the chip
address setting is not performed. While XMODE is Low and the micro-controller is not used the state
of the chip address setting pin is undefined,. Be sure to connect either A pull-down resistor or a pull-
up resistor should be connected to EMPHA/UO and AUDIO /VO.
AUDIO /VO
Pull-down
Pull-down
Pull-up
EMPHA/UO
Pull-down
Pull-up
CAU
CAL
0
0
1
1
0
1
0
1
Pull-down
Pull-up
Pull-up
Table 2 Chipset Address Settings
WM8802
Pull-up 10kΩ
EMPH/UO
AUDIO/VO
External
Circuit
CKST
INT
Pull-down 10kΩ
Figure 4 Function Setting Input Pin Setting Example
Notes:
1. Chip address setting
2. Demodulation function master or slave setting
=> CAL = CAU = 0
=> Master
3. Modulation function or general purpose I/O port switch => General purpose I/O port
function
PP Rev 1.1 April 2004
11
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
