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PYF.1
PYF.1
Associate
March 1, 2023
Question

How to respond NACK to Master

  • March 1, 2023
  • 2 replies
  • 999 views

Hello everyone,

I have a application on STM32L5xx, I configuration I2C1 to slave mode,

when slave receive first unwanted command code, I want to response NACK to master. I judge the command code in AL_SMBUS_SlaveRxCpltCallback call back function, and set NACK bit at CR2 register but unfortunately cannot success.

This topic has been closed for replies.

2 replies

Bubbles
Bubbles
ST Employee
March 2, 2023

Hi @PYF.1​ ,

to get the ACK control, you need to configure slave byte control mode. The settings are SBC=1, RELOAD=1, NBYTES=1. NOSTRETCH=0. The slave byte control is a whole chapter in the reference manual.

BR,

J

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PYF.1
PYF.1Author
Associate
March 3, 2023

Hi JUUDO,

Thanks for your answer, here I ignore the RELOAD=1, now I could control the ACK at eacch byte

determine response ACK/NACK to master

BR

PYF

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