Fibocom MG661-EU - Status Indication

3 Application Interfaces
37
The I2C bus is a simple, bidirectional two-wire synchronous serial bus. It only requires a data
line and a clock line to transfer information between devices connected to the bus. It is mainly
used in the communication between multiple integrated circuits (ICs) in the system.
Schematic Diagram Design
The module I2C interface has been pulled up by software by default, and external hardware
pull-up is required to be reserved.
When I2C has more than one peripheral, please ensure the uniqueness of every peripheral
address. When some peripherals need to occupy I2C bus frequently, it is not recommended
to share it with other devices.
The I2C supports standard mode 100Kbps and fast mode 400Kbps communication rates.
PCB Design
I2C PCB traces and peripherals require protection from interference.
3.3.4 PCM/I2S
The MG661 module enables external codec.
Table 26. PCM/I2S interface description
Pin No.
Pin Name
I/O
Power
Domain
Description
30
PCM_CLK
DO
1.8V
PCM clock
31
PCM_SYNC
DO
1.8V
PCM data synchronization signal
32
PCM_DIN
DI
1.8V
PCM data input
33
PCM_DOUT
DO
1.8V
PCM data output
6
I2S_MCLK
DO
1.8V
I2S main clock output signal
Background