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Modifications reserved |Data subject to change without notice | Printed in Germany

Document number: BST-BMP388-DS001-07 Revision_1.7_112020

The I²C interface uses the following pins:

•

SCK: serial clock (SCL)

•

SDI:

data (SDA)

•

SDO: Slave address LSB (GND = ‘0’, VDDIO = ‘1’)

The CSB is not used and is left open. SDI is bi-directional with open drain to VSS: it must be externally connected to VDDIO

via a pull up resistor. Refer to chapter 6 for connection instructions.

The following abbreviations will be used in the I²C protocol figures:

•

Start

•

Stop

•

ACKS

Acknowledge by slave

•

ACKM

Acknowledge by master

•

NACKM

Not acknowledge by master

5.2.1. I²C write

Writing is done by sending the slave address in write mode (RW = ‘0’), resulting in slave address 111011X0 (‘X’ is determined

by state of SDO pin. Then the master sends pairs of register addresses and register data. The transaction is ended by a stop

condition. This is depicted in Figure 15.

Figure 15: I²C write

5.2.2. I²C read

To be able to read registers, first the register address must be sent in write mode (slave address 111011X0). Then either a

stop or a repeated start condition must be generated. After this the slave is addressed in read mode (RW = ‘1’) at address

111011X1, after which the slave sends out data from auto-incremented register addresses until a NOACKM and stop

condition occurs. This is depicted in Figure 16, where two bytes are read from register 0xF6 and 0xF7.

Figure 16: I²C multiple byte read

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