BMA253
Data sheet
Page 102
Figure 18 shows the definition of the I²C timings given in Table 23:
SDA
tBUF
tf
tLOW
SCL
tHIGH
tHDDAT
tr
tHDSTA
tSUDAT
SDA
tSUSTA
tSUSTO
Figure 18: 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
ACKM
NACKM
RW
Acknowledge by slave
Acknowledge by master
Not acknowledge by master
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.
BST-BMA253-DS000-01 | Revision 1.0 | August 2015
Bosch Sensortec
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Note: Specifications within this document are subject to change without notice.
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