topic Re: Clock Stretching in Kinetis Microcontrollers

Clock Stretching

perharaldhelges — Fri, 20 Mar 2015 13:50:40 GMT

I`m trying to do some clock streching by using th I2C_LDD componenet but the clock stretching option doesn`t seem to be avalable ?

Re: Clock Stretching

egoodii — Fri, 20 Mar 2015 19:05:06 GMT

I presume you are speaking of a mode where the Kinetis is an I2C slave. In that case, the 'clock stretching' is an automatic hardware function, where the clock line will be held after a byte is received until the I2C register has been cleared by firmware, thus making it available for the next byte to be clocked-in.

Re: Clock Stretching

perharaldhelges — Mon, 23 Mar 2015 08:10:13 GMT

No, I`m using Kinetis KL26Z as master. The I2C_LDD component has an option for clock streching but it is not possible to mark it.

Re: Clock Stretching

egoodii — Mon, 23 Mar 2015 13:36:22 GMT

Well, I don't know what to tell you. Per the I2C standard, 'clock stretching' is strictly a function FROM a slave BACK to a master to 'pace' the transaction. Master-side I2C is, of course, totally 'in control' of its own pacing. Thus the I2C_LDD component doesn't enable 'clock stretching' as an option in master-mode.