N720 OpenLinux
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
35
3.3.6 I2S/PCM
Signal
Pin
I/O
Function
Remarks
I2S_MCLK
64
DO
I2S main clock
12.288 MHz by default
I2S_1_SCLK
9
DO
I2S serial clock
Multiplexed as PCM_CLK
I2S_1_DOUT
10
DO
I2S data transmit
Multiplexed as PCM_DOUT
I2S_1_DIN
11
DI
I2S data receive
Multiplexed as PCM_DIN
I2S_1_WS
12
B
I2S word select
Multiplexed as PCM_SYNC
N720 OpenLinux provides one I2S/PCM multiplex interface that supports 1.8V. Figure 3-24 shows I2S
connection.
Figure 3-24 I2S connection
I2S_TX
I2S_RX
I2S_WS
I2S_SCLK
N720 module
Codec
I2S_MCLK
I2S_MCLK
I2S_DIN
I2S_DOUT
I2S_LRCLK
I2S_BCLK
Schematic Design Recommendations
If the levels of N720 OpenLinux and CODEC do not match, add a level shift circuit as shown in
3.3.4.
Leave I2S_MCLK floating in your application if it is not required for the CODEC chipset selected.
PCB Design Guidelines
Do not cross other traces if possible. If crossing is inevitable, route the I2S traces perpendicular
to other traces.
Keep I2S traces far away from areas that might introduce ESD.
Surround I2S_MCLK signal traces with ground.
The I2S function complies with Phillips I2S Bus Specifications revised June 5, 1996.