ICM-20690
6 DIGITAL INTERFACE
6.1 I2C AND SPI SERIAL INTERFACES
The internal registers and memory of the ICM-20690 can be accessed using either I2C at 400 kHz or SPI at 10 MHz. SPI operates in
four-wire mode.
Pin Number
Pin Name
Pin Description
Application Processor (AP) Interface: AP I2C slave address LSB (AP_AD0); AP SPI serial
data output (AP_SDO)
1
AP_AD0 / AP_SDO
12
13
14
AP_CS
AP SPI Chip select (SPI mode only)
AP_SCL / AP_SCLK
AP_SDA / AP_SDI
AP I2C serial clock (AP_SCL); AP SPI serial clock (AP_SCLK)
AP I2C serial data (AP_SDA); AP SPI serial data input (AP_SDI)
Table 14. Serial Interface
Note:
To prevent switching into I2C mode when using SPI, the I2C interface should be disabled by setting the I2C_IF_DIS configuration bit.
Setting this bit should be performed immediately after waiting for the time specified by the “Start-Up Time for Register Read/Write”
in Section 6.3.
For further information regarding the I2C_IF_DIS bit, please refer to sections 11 and 12 of this document.
6.2 I2C INTERFACE
I2C is a two-wire interface comprised of the signals serial data (SDA) and serial clock (SCL). In general, the lines are open-drain and bi-
directional. In a generalized I2C interface implementation, attached devices can be a master or a slave. The master device puts the
slave address on the bus, and the slave device with the matching address acknowledges the master.
The ICM-20690 always operates as a slave device when communicating to the system processor, which thus acts as the master. SDA
and SCL lines typically need pull-up resistors to VDD. The maximum bus speed is 400 kHz.
The slave address of the ICM-20690 is b110100X, which is 7 bits long. The LSB bit of the 7-bit address is determined by the logic level
on pin AD0. This allows two ICM-20690s to be connected to the same I2C bus. When used in this configuration, the address of one of
the devices should be b1101000 (pin AD0 is logic low) and the address of the other should be b1101001 (pin AD0 is logic high).
Page 27 of 76
Document Number: DS-000178
Revision: 1.0
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