Datasheet

BMM150 Geomagnetic Sensor

Page 38

BST-BMM150-DS001-01 | Revision 1.0 | April 2013

Bosch Sensortec

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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.

Figure 13 the definition of the I²C timings given in Table 31:

Figure 13: I²C timing diagram

The I²C protocol works as follows:

START: Data transmission on the bus begins with a high to low transition on the SDA line while

SCL 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.

STOP: 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 SCL is held high.

ACK: Each byte of data transferred must be acknowledged. It is indicated by an acknowledge

bit sent by the receiver. The transmitter must release the SDA line (no pull down) during the

acknowledge pulse while the receiver must then pull the SDA line low so that it remains stable

low during the high period of the acknowledge clock cycle.

In the following diagrams these abbreviations are used:

S

Start

P

Stop

ACKS

Acknowledge by slave

ACKM

Acknowledge by master

NACKM

Not acknowledge by master

RW

Read / Write

A START immediately followed by a STOP (without SCK toggling from logic “1” to logic “0”) is

not supported. If such a combination occurs, the STOP is not recognized by the device.

S

D

A

S

C

L

S

D

A

A