Bosch MAN-REG-X-08 Especificaciones descargar pdf (Pagina 43)

Data sheet

BMA220

Page 43

BST-BMA220-DS003-08 | Revision 1.15 | August 2011 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.

7.3 I²C interface

The I²C interface on board is a slave bus. Two signal lines SCL and SDA are used for

communication. SDA is a bidirectional line used for sending and receiving data to/from the

interface. SCL is the serial clock line used to synchronize the data. Both lines are connected to

VDD via pull-up resistors. So the lines are pulled high when the bus is free. The lines are low

only when any of the transmitters drives ‘0’. The on-board I²C interface supports standard and

fast-mode I²C.

Important note:

The default slave address assigned to the BMA220 is 000 1011. When in I²C mode, the LSB

can be inverted by tying the CSB pin to ‘1’. This allows resolving conflicts with existing devices.

I²C protocol

Start and stop conditions (see figure 18):

Data transmission on the bus begins with a HIGH to LOW transition on SDA line while SCK is

held high (start condition (S) indicated by I²C bus master). Once the START signal is transferred

by the master, the bus is considered busy.

Each data transfer should be terminated by a Stop signal (P) generated by master. The STOP

condition is a LOW to HIGH transition on SDA line while SCK is held high.

SCK

SDA

SUSTA

SUSTO

HDSTA

Figure 19: Waveform diagram for I²C start and stop conditions

1 2 ... 38 39 40 41 42 43 44 45 46 47 48 ... 62 63

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Bosch MAN-REG-X-08 Especificaciones Pagina 43