ST STM32WL5 Series Reference Manual page 1099

Advanced arm-based 32-bit mcus with sub-ghz radio solution

Hide thumbs Also See for STM32WL5 Series:

Table of Contents

SMBus Slave receiver

When the I2C is used in SMBus mode, SBC must be programmed to '1' in order to allow the

PEC checking at the end of the programmed number of data bytes. In order to allow the

ACK control of each byte, the reload mode must be selected (RELOAD=1). Refer to

byte control mode on page 1072

In order to check the PEC byte, the RELOAD bit must be cleared and the PECBYTE bit

must be set. In this case, after NBYTES-1 data have been received, the next received byte

is compared with the internal I2C_PECR register content. A NACK is automatically

generated if the comparison does not match, and an ACK is automatically generated if the

comparison matches, whatever the ACK bit value. Once the PEC byte is received, it is

copied into the I2C_RXDR register like any other data, and the RXNE flag is set.

In the case of a PEC mismatch, the PECERR flag is set and an interrupt is generated if the

ERRIE bit is set in the I2C_CR1 register.

If no ACK software control is needed, the user can program PECBYTE=1 and, in the same

write operation, program NBYTES with the number of bytes to be received in a continuous

flow. After NBYTES-1 are received, the next received byte is checked as being the PEC.

The PECBYTE bit has no effect when the RELOAD bit is set.

Inter-integrated circuit (I2C) interface

for more details.

RM0453 Rev 1

Need help?

Do you have a question about the STM32WL5 Series and is the answer not in the manual?