Wi-Fi&Bluetooth Module Series
FCM561D-P_Hardware_Design
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signals, as well as noise signals such as clock signals and DC-DC signals.
⚫
The distance between SDIO signals and other signals must be greater than twice the trace width,
and the bus load capacitance must be less than 15 pF.
⚫
SDIO signal traces (SDIO_CLK and SDIO_DATA[0:3]/SDIO_CMD) need to be equal in length (less
than 1 mm distance between the traces).
3.4.5. I2C Interfaces
In the case of multiplexing, the module supports up to 2 I2C interfaces which can operate in master or
slave mode. The interfaces support standard (up to 100 Kbps) and fast (up to 400 Kbps) modes with
7-bit and 10-bit addressing. If low level on SCL or bus idle duration is greater than a programmable
threshold, it will generate interrupt to MCU.
Table 11: Pin Definition of I2C Interfaces
Reserve 1
–10 kΩ pull-up resistors to VBAT when I2C1 and I2C2 interfaces are connected to an
external equipment.
3.4.6. USB Interface
The module provides an USB interface compliant with USB 1.1 and 2.0 specifications. It can operate as
a host or a device and supports full-speed operation (up to 12 Mbps).
Table 12: Pin Definition of USB Interface
Pin Name
Pin No.
Multiplexing Function I/O
Description
Comment
GPIO20
30
I2C1_SCL
DIO
I2C1 serial clock
GPIO21
29
I2C1_SDA
DIO
I2C1 serial data
GPIO0
40
I2C2_SCL
DIO
I2C2 serial clock
Other I2C2
configurations, see
GPIO1
39
I2C2_SDA
DIO
I2C2 serial data
Pin Name
Pin No.
I/O
Description
Comment
USB_DP
6
AIO
USB 2.0 differential
data (+)
USB 2.0 compliant.
Requires 85
–100 Ω differential
NOTE