Getting Started with I2C: What is Clock Stretching?

In I2C(Inter-Integrated Circuit) communication, the master device initiates the communication by sending a start condition and then sending the slave device’s address. The slave device then responds with an ACK (acknowledge) signal to indicate that it has received the address correctly. If the slave device needs more time to process the data, it can hold the clock signal low to pause the communication temporarily. This is known as clock stretching.

Clock stretching is a technique used in communication protocols to allow slower devices to slow down the clock signal of a faster device. This technique is commonly used in I2C communication, where the clock stretching is performed by the slave device. This is useful in scenarios where multiple devices of different speeds are connected to the same bus.

However, clock stretching can also cause timing issues if not implemented correctly. If the slave device holds the clock signal low for too long, the master device may interpret it as a communication failure and terminate the transaction. Additionally, if multiple slaves are present on the bus and one of them holds the clock signal low, it can delay the entire communication, affecting the timing of other transactions.

For more details please refer the link shared below:

https://embeddedwala.com/Blogs/DigitalCommunication/Getting-Started-with-I2C:-What-is-Clock-Stretching

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