Specifications

BMA180
Preliminary data sheet
Bosch Sensortec
Rev. 1.0 Page 27 / - proprietary information - 06 March 2009
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Specifications within this document are preliminary and subject to change without notice. Document is not intended for publication.
7.4 Register arithmetic
The following arithmetic is used for memory registers.
Register Format Bit width
OFFSET
X|Y|Z
offset binary 3x12
GAIN
X|Y|Z
offset binary 3x7
TCO
X|Y|Z
offset binary 3x6
TCS offset binary 4
A
X|Y|Z
(acceleration
values)
2's complement 3x14
Temp. 2's complement 8
THRESHOLD
(TH or TH_X|Y|Z)
unsigned positive 8
HYSTERESIS
(HY or HY_X|Y|Z)
unsigned positive 5
7.5 EEPROM
7.5.1 General information
The embedded EEPROM memory is used to trim analogue parameters and to set-up the
interrupt function; it is organized in 16 words of 16 bits (each word contains 2x8 bits).
Each EEPROM data has a corresponding image which is used to latch EEPROM data. Image
content act on analog part, it is also used as buffer to read and write to EEPROM. EEPROM
data are downloaded into image registers after each of the following events:
- Power On Reset
- Reset command sent through interface (soft reset)
- Control bit update_image set to ‘1’.
7.5.2 EEPROM reading
No direct EEPROM reading is implemented; result of reading addresses 40h to 5Fh returns
content of addresses 20h to 3Fh.
For Reading the EEPROM registers it is possible to download the EEPROM registers in to the
image registers by setting update_image=1 and read out the corresponding image register.
7.5.3 EEPROM writing
Writing to EEPROM is locked by default to prevent mal-function. To unlock writing in the image
registers of the non-protected area, set ee_w to ‘1’.