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MPU-9250 Register Map and Descriptions

Document Number: RM-MPU-9250A-00

Revision: 1.4

Release Date: 9/9/2013

BIT

NAME

FUNCTION

[7:0]

D[7:0]

Low byte of the Z-Axis gyroscope output

GYRO_ZOUT =

Gyro_Sensitivity * Z_angular_rate

Nominal

Conditions

FS_SEL = 0

Gyro_Sensitivity = 131 LSB/(º/s)

4.25 Registers 73 to 96 – External Sensor Data

EXT_SENS_DATA_00 – 23

Serial IF: SyncR

Reset value: 0x00

24 registers with the same description as below:

BIT

NAME

FUNCTION

[7:0]

D[7:0]

Sensor data read from external I2C devices via the I2C

master interface. The data stored is controlled by the

I2C_SLV(0-4)_ADDR, I2C_SLV(0-4)_REG, and

I2C_SLV(0-4)_CTRL registers

Description:

These registers store data read from external sensors by the Slave 0, 1, 2, and 3 on the auxiliary I

interface. Data read by Slave 4 is stored in I2C_SLV4_DI (Register 53).

External sensor data is written to these registers at the Sample Rate as defined in Register 25. This

access rate can be reduced by using the Slave Delay Enable registers (Register 103).

Data is placed in these external sensor data registers according to I2C_SLV0_CTRL,

I2C_SLV1_CTRL, I2C_SLV2_CTRL, and I2C_SLV3_CTRL (Registers 39, 42, 45, and 48). When

more than zero bytes are read (I2C_SLVx_LEN > 0) from an enabled slave (I2C_SLVx_EN = 1), the

slave is read at the Sample Rate (as defined in Register 25) or delayed rate (if specified in Register

52 and 103). During each sample cycle, slave reads are performed in order of Slave number. If all

slaves are enabled with more than zero bytes to be read, the order will be Slave 0, followed by Slave

1, Slave 2, and Slave 3.

Each enabled slave will have EXT_SENS_DATA registers associated with it by number of bytes read

(I2C_SLVx_LEN) in order of slave number, starting from EXT_SENS_DATA_00. Note that this

means enabling or disabling a slave may change the higher numbered slaves’ associated registers.

Furthermore, if fewer total bytes are being read from the external sensors as a result of such a

change, then the data remaining in the registers which no longer have an associated slave device

(i.e. high numbered registers) will remain in these previously allocated registers unless reset.

If the sum of the read lengths of all SLVx transactions exceed the number of available

EXT_SENS_DATA registers, the excess bytes will be dropped. There are 24 EXT_SENS_DATA

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