Data Sheet

Sensors

Freescale Semiconductor 21

MMA8452Q

Data Registers: 0x01 OUT_X_MSB, 0x02 OUT_X_LSB, 0x03 OUT_Y_MSB, 0x04 OUT_Y_LSB, 0x05 OUT_Z_MSB, 0x06

OUT_Z_LSB

These registers contain the X-axis, Y-axis, and Z-axis 12-bit output sample data expressed as 2's complement numbers. The

sample data output registers store the current sample data.

OUT_X_MSB, OUT_X_LSB, OUT_Y_MSB, OUT_Y_LSB, OUT_Z_MSB, and OUT_Z_LSB are stored in the auto-

incrementing address range of 0x01 to 0x06 to reduce reading the status followed by 12-bit axis data to 7 bytes. If the F_READ

bit is set (0x2A bit 1), auto increment will skip over LSB registers. This will shorten the data acquisition from

7 bytes to 4 bytes. The LSB registers can only be read immediately following the read access of the corresponding MSB register.

A random read access to the LSB registers is not possible. Reading the MSB register and then the LSB register in sequence

ensures that both bytes (LSB and MSB) belong to the same data sample, even if a new data sample arrives between reading the

MSB and the LSB byte.

0x0B: SYSMOD System Mode Register

The system mode register indicates the current device operating mode. Applications using the Auto-SLEEP/WAKE mechanism

should use this register to synchronize the application with the device operating mode transitions.

0x01 OUT_X_MSB: X_MSB Register (Read Only)