BMA020 Bosch Sensortec, BMA020 Datasheet - Page 18

• Manufacturer Part Number: BMA020
• Description: 3-AXIS ACCELEROMETER DIGITAL I/F
• Manufacturer: Bosch Sensortec

Specifications of BMA020

• Axis: X, Y, Z
• Acceleration Range: ± 2g, 4g, 8g
• Sensitivity: 256LSB/g, 128LSB/g, 64LSB/g
• Voltage - Supply: 2 V ~ 3.6 V
• Output Type: Digital
• Bandwidth: 3kHz
• Interface: I²C, SPI
• Mounting Type: Surface Mount
• Package / Case: 12-LGA
• For Use With: 828-1014 - BMA020 TRIBOX DEMO BOARD W/USB828-1008 - BMA020 DAUGHTERCARD FOR DEV KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 828-1000-2

3.2.10 New_data_int
If this bit (address 15h, bit 5) is set to 1, an interrupt will be generated when all three axes
acceleration values are new, i.e. BMA020 updated all acceleration values after latest serial
read-out. Interrupt generated from new data detection is a latched one; microcontroller has to
write reset_INT at 1 after interrupt has been detected high (section 3.3.1). This interrupt is also
reset by any acceleration byte read procedure (read access to address 02h to 07h).
New data interrupt always occurs at the end of the Z-axis value update in the output register
(3kHz rate). Following figure shows two examples of X-axis read out and the corresponding
interrupt generation.
Figure 3: Explanation of new data interrupt.
left side - read out command of x-axis prior to next x-axis conversion
right side - read out of x-axis send after x-axis conversion
Please refer to chapter 8.1 for more details.
Note: When using the I
330µs (depending on I
data read out sequence may lead to the situation that the new_data_int may not be cleared right
in time. This must be considered and taken care of properly.
Rev. 1.2
© 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.
Note: Specifications within this document are subject to change without notice.
X-axis value read out
T
conversion
→ new data interrupt after completion of current conversion cycle after z-axis
→ new data interrupt at the end of next period when x axis has been updated
New data interrupt
X
Y
Z
T
X-axis value read out
2
2
C interface for data transfer, the data read out phase can be longer than
C clock frequency and the amount of data transmitted). Starting a new
X
Y
Digital, triaxial acceleration sensor
Z
T
X
X-axis value read out
New data interrupt
Y
Data sheet
BMA020
Page 18
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Z
T
New data interrupt
X
Y
Z
T
X-axis value read out
X
Y
Z
T
X
New data interrupt
Y
Bosch Sensortec
Z
30 May 2008