Specifications

BMA180
Preliminary data sheet
Bosch Sensortec
Rev. 1.0 Page 26 / - proprietary information - 06 March 2009
© Bosch Sensortec GmbH reserves all rights even in the event of industrial property rights. We reserve all rights of disposal such
as copying and passing on to third parties. BOSCH and the symbol are registered trademarks of Robert Bosch GmbH, Germany.
Specifications within this document are preliminary and subject to change without notice. Document is not intended for publication.
− Interrupt settings
Read /
Write
volatile
EEPROM
− Default settings of functional and
interrupt settings
− Trimming values
− Customer reserved data storage
− Bosch Sensortec Reserved Memory
Write
Write
Write
Write
non-volatile
non-volatile
non-volatile
non-volatile
- The global memory mapping contains EEPROM and latches.
- All EEPROM registers are duplicated into the corresponding image registers.
- Writing to unused bits has no effect on the IC; reading unused bits leads to undefined level.
- Image registers are used to download the EEPROM content to be able to act on IC
functions. Registers 20h to 3Fh thus directly correspond to EEPROM bytes 40h to 5Fh.
7.2 Registers
There are 5 types of registers in the sensor – test, control, image, status and data registers. All
registers are 8-bit. Image and control registers are accessible in read/write mode by the user.
- Test registers are reserved for Bosch, they are not described here. They are not accessible
to the customer.
- Control registers are used to set-up the functional mode of IC. See next paragraphs for
detailed description of each bit. Few bits are one-shot control bits.
- Status registers contain useful information about the alert/interrupt modes and to know if
new acceleration data is available since latest read-out.
- Image registers contain EEPROM values and are downloaded after release of POR, soft-
reset or when the update_image command is send to BMA180. Writing to these registers
has no effect on EEPROM content. Image registers can directly be accessed to trim the
device without using any EEPROM write procedure in case of several iterations during
calibration. Image registers can also be used to overwrite BMA180 settings defined in the
EEPROM memory. It is possible to come back to EEPROM memory settings at anytime by
writing update_image control bit to 1.
- Data registers contain the 3 acceleration values, the temperature value and information
about the chip (see 7.13.3)
7.3 Programming of the calibration parameters
The full-sensor functionality and precision is provided by trimming the sensor on wafer level and
on sensor level during End-of-Line testing. In order to achieve highest precision (e. g. offset
accuracy) even after soldering the device onto a PCB, the user can recalibrate the trimming
correction values after mounting (see section 9.4.1).