TWI I2C interface without clock stretch

RE: TWI I2C interface without clock stretch

Håkon Alseth — Mon, 28 Oct 2024 09:21:43 GMT

Hi,

Thank you for explaining your scenario in detail.

Unfortunately, it is not possible to turn off clock stretching feature in hardware.

Kind regards,

Håkon

RE: TWI I2C interface without clock stretch

chianglin — Mon, 28 Oct 2024 09:19:57 GMT

Hi,

Under normal circumstances, since the twi of nRF52832 belongs to the I2C master, when the I2C slave pulls SCL Low, the twi of nrf52832 will generate Clock stretch.
What I want to do is: twi does not detect whether SCL is pulled Low by the I2C-Slave device, but continues to send data

Thank you

RE: TWI I2C interface without clock stretch

Håkon Alseth — Mon, 28 Oct 2024 08:54:38 GMT

Clock stretching happens when the slave pulls the SCL line low. As long as your external device does not do this, then it is OK.

Kind regards,

Håkon

RE: TWI I2C interface without clock stretch

chianglin — Mon, 28 Oct 2024 08:24:05 GMT

Hi,

Thank you for your explanation.

What I want to do has nothing to do with the type of Slave.
The test I want to do is: I want the waveform sent by the TWI interface not to have the stretch function to verify whether the slave device can accept non-stretch TWI signals.
Therefore, I want to turn off the stretch function of the nRF52832 TWI interface.

Thank you

RE: TWI I2C interface without clock stretch

Håkon Alseth — Mon, 28 Oct 2024 08:09:02 GMT

Clock stretching is a feature that the TWIM supports, and it is up to the connected TWI slave device to perform this operation. Please note that not all slaves perform clock stretching. I would recommend checking the specification of your connected sensor for its timing details if you are seeing excessive clock stretching.

Could you explain the issues you're seeing with clock stretching?

Kind regards,

Håkon