WM8711 Wolfson Microelectronics Ltd., WM8711 Datasheet - Page 25

• Manufacturer Part Number: WM8711
• Description: Internet Audio DAC With Integrated Headphone Driver
• Manufacturer: Wolfson Microelectronics Ltd.

WM8711
ACTIVATING DSP AND DIGITAL AUDIO INTERFACE
SOFTWARE CONTROL INTERFACE
WOLFSON MICROELECTRONICS LTD
To prevent any communication problems from arising across the Digital Audio Interface is disabled
(tristate with weak 100k pulldown) at power on. Once the Audio Interface and the Sampling Control
has been programmed it is activated by setting the ACTIVE bit under Software Control.
Table 16 Activating DSP and Digital Audio Interface
It is recommended that between changing any content of Digital Audio Interface or Sampling Control
Register that the active bit is reset then set.
The software control interface may be operated using either a 3-wire or 2-wire MPU interface.
Selection of interface format is achieved by setting the state of the MODE pin.
In 3-wire mode, SDIN is used for the program data, SCLK is used to clock in the program data and
CSB is used to latch in the program data. In 2-wire mode, SDIN is used for serial data and SCLK is
used for the serial clock. In 2-wire mode, the state of CSB pin allows the user to select one of two
addresses.
SELECTION OF SERIAL CONTROL MODE
The serial control interface may be selected to operate in either 2 or 3-wire modes. This is achieved
by setting the state of the MODE pin.
Table 17 Control Interface Mode Selection
3-WIRE (SPI COMPATIBLE) SERIAL CONTROL MODE
The WM8711 can be controlled using a 3-wire serial interface. SDIN is used for the program data,
SCLK is used to clock in the program data and CSB is use to latch in the program data. The 3-wire
interface protocol is shown in Figure 19.
Figure 19 3-Wire Serial Interface
Notes:
1.
2.
2-WIRE SERIAL CONTROL MODE
The WM8711 supports a 2-wire MPU serial interface. The device operates as a slave device only.
The WM8711 has one of two slave addresses that are selected by setting the state of pin 10, (CSB).
0001001
Active Control
B[15:9] are Control Address Bits
B[8:0] are Control Data Bits
REGISTER
ADDRESS
SCLK
SDIN
CSB
MODE
0
1
B15
B14
0
BIT
B13
B12
ACTIVE
B11
LABEL
INTERFACE
B10
FORMAT
2 wire
3 wire
B9
0
B8
DEFAULT
B7
B6
B5
Activate Interface
1 = Active
0 = Inactive
B4
DESCRIPTION
PP Rev 1.2 November 2000
B3
B2
B1
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B0
25