Datasheet

ADAU1381
Rev. B | Page 83 of 84
Register 16628 (0x40F4), Serial Data/GPIO Pin
Configuration
Bits[3:0], GPIO[0:3]
The serial data/GPIO pin configuration register controls the
functionality of the serial data port pins. If the bits in this
register are set to 1, then the GPIO[0:3] pins become GPIO
interfaces to the sound engine. If these bits are set to 0, they
remain LRCLK, BCLK, or serial port data pins, respectively.
Register 16630 (0x40F6), Sound Engine Run
Bit 0, Sound Engine Run
This bit, in conjunction with the sound engine frame rate, initiates
audio processing in the sound engine. When this bit is enabled,
the program counter begins to increment when a new frame of
audio data is input to the sound engine. When this bit is disabled,
the sound engine goes into standby mode.
Before going into standby mode, the following sequence must
be performed:
1. Set the sound engine frame rate in Register 16619 to
0x7F (none).
2. Wait 3 ms .
3. Set the sound engine run bit in Register 16630 to 0x00.
When reenabling the sound engine run bit, the following
sequence must be followed:
1. Set the sound engine frame rate in Register 16619 to an
appropriate value.
2. Set the sound engine run bit in Register 16630 to 0x01.
Register 16632 (0x40F8), Serial Port Sampling Rate
Bits[2:0], Serial Port Control Sampling Rate
These bits set the serial port sampling rate as a function of the
audio sampling rate, f
S
. In most applications, the serial port
sampling rate, sound engine sampling rate, and ADC and DAC
sampling rates should be equal.
Table 74. Serial Data/GPIO Pin Configuration Register
Bits Description Default
[7:4] Reserved
3 GPIO0 0
0: LRCLK
1: GPIO enabled
2 GPIO1 0
0: BCLK
1: GPIO enabled
1 GPIO2 0
0: serial data output
1: GPIO enabled
0 GPIO3 0
0: serial data input
1: GPIO enabled
Table 75. Sound Engine Run Register
Bits Description Default
[7:1] Reserved
0 Sound engine run 0
0: sound engine standby
1: run the sound engine
Table 76. Serial Port Sampling Rate Register
Bits Description Default
[7:3] Reserved
[2:0] Serial port control sampling rate 000
000: f
S
/1 (48 kHz)
001: f
S
/6 (8 kHz)
010: f
S
/4 (12 kHz)
011: f
S
/3 (16 kHz)
100: f
S
/2 (24 kHz)
101: f
S
/1.5 (32 kHz)
110: f
S
/0.5 (96 kHz)
111: reserved