WM8711BL Wolfson Microelectronics, WM8711BL Datasheet - Page 30

• Manufacturer Part Number: WM8711BL
• Description: Ultra-Small Audio DAC
• Manufacturer: Wolfson Microelectronics

WM8711BL
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ACTIVATING DSP AND DIGITAL AUDIO INTERFACE
SOFTWARE CONTROL INTERFACE
The exact sample rates supported for all combinations are defined by the relationships in Table 15
below.
Table 15 USB Mode Actual Sample Rates
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
8
32
44.1
48
88.2
96
0001001
Active Control
SAMPLING
TARGET
RATE
REGISTER
ADDRESS
kHz
MODE
0
1
8
12MHz/(250 x 48/8)
32
12MHz/(250 x 48/32)
not available
48
12MHz/250
not available
96
12MHz/125
0
BOSR=0
( 250FS)
BIT
kHz
ACTUAL SAMPLING RATE
ACTIVE
LABEL
INTERFACE
FORMAT
2 wire
3 wire
8.021
12MHz/(272 x 11/2)
not available
44.117
12MHz/272
not available
88.235
12MHz/136
not available
0
DEFAULT
BOSR=1
(272FS)
kHz
Activate Interface
1 = Active
0 = Inactive
DESCRIPTION
PD, Rev 4.1, April 2007
Production Data
30