AS3460
Evaluation Board
Demo Kit Manual
• PUBLIC
UG000480
• v3-00 • 2021-Nov-08
126
│ 26
Figure 39:
Raspberry Pi Board Used For I
2
C Interface
3.9
I
2
S Selection
The AS3460 does support one stereo I
2
S input and two stereo output channels. The primary I
2
S
interface I2S#0 (SCLK0, LRCK0, SDI0 and SDO0) is used to receive audio data from an I
2
S master
host device which can be for example a BT SoC or Digital Signal processor. The received stereo
audio data is fed into an Asynchronous Sample Rate Converter (ASRC1) to synchronize it to the
internal clock domain of AS3460. The output of ASRC is fed into the AHE for additional signal
processing and audio playback. The stereo audio output (SDO0) at I2S#0 interface allows to send for
example raw microphone data back to the host. This function allows sharing for example the ANC
microphones to be used as voice call microphones. In order to be synchronous to the host the audio
data is synchronized via a second four channel ASRC2 to the primary I
2
S interface.
Figure 40:
I
2
S Interface
– Block Diagram
The second I
2
S interface I2S#1 does support one stereo output only. This allows sending out two
additional audio channels back to the host to apply algorithms or further enhance the audio signal.
I2S#1 interface receives its data from ASRC2, which can support up to six different input channels for
highest system flexibility when developing software algorithms on the host system making use of the
I2
S#
0
SCLK0
LRCK0
SDI0
SDO0
ASRC1
2 channels
AHE
I2
S#
1
Left
Right
ASRC2
4 channels
GPIO_Ax
GPIO_Ax
GPIO_Ax
SW1
Left
Right
M
UX
4
6 alternative
inputs to ASRC2
Bit Clock
Frame Clock
Stereo Data Input
Stereo Data Output
Bit Clock
Frame Clock
Stereo Data Output
HOST
e.g. BT SoC,
DSP
I2
S
M
as
te
r 1
I2
S M
as
te
r 2
CH1
CH2
CH3
CH4
