BMC150 datasheet(34/142 Pages) BOSCH

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Datasheet

eCompass BMC150

Page 34

BST-BMC150-DS000-04 | Revision 1.0 | July 2014

Bosch Sensortec

third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.

Note: Specifications within this document are subject to change without notice. Not intended for publication.

The public offset compensation registers (0x38) offset_x, (0x39) offset_y, (0x3A) offset_z are

images of the corresponding registers in the NVM. With each image update (see section 4.6 for

details) the contents of the NVM registers are written to the public registers. The public register

can be over-written by the user at any time. After changing the contents of the public registers

by either an image update or manually, all 8bit values are extended to 12bit values for internal

computation. In the opposite direction, if an internally computed value changes it is converted to

an 8bit value and stored in the public register.

Depending on the selected g-range the conversion from 12bit to 8bit values can result in a loss

of accuracy of one to several LSB. This is shown in

Figure 7.

In case an internally computed compensation value is too small or too large to fit into the

corresponding register, it is saturated in order to prevent an overflow error.

By writing ´1´ to the (0x36) offset_reset bit, all offset compensation registers are reset to zero.

BMC150 Datasheet(PDF) 34 Page - Bosch Sensortec GmbH