User's Manual

Table Of Contents
SIM7090G User Manual V1.01
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Figure 18: I2C reference circuit
The I2C signal has no pull-up resistors in module. So the pulling up resistors 1KR to VDD_EXT is
necessary in application circuit.
3.8 SPI Interface
SIM7090G supports a set of 4- wire (MISO, MOSI, CS and CLK) SPI interfaces and supports both SPI
master mode and SPI slave mode. The maximum clock frequency is up to 50MHz when operating in SPI
master mode and up to 25MHz when operating in SPI Slave mode.
Table 17: Pin Definition of SPI Interface
Pin Name
Pin No.
I/O
Description
Comment
*SPI_MOSI
40
DO
SPI master-out slave-in
1.8V power domain
SPI_MISO
8
DI
SPI master-in slave-out
1.8V power domain
SPI_CS_N
63
DO
SPI chip select
1.8V power domain
SPI_CLK
9
DO
SPI clock
1.8V power domain
SPI_MOSI is FAST BOOT function before system boot-up, so the level on this pin cannot be high
before the system boot-up, otherwise the module will not start normally.
NOTE