TM4C1290NCPDT: Tr/Tf Specifications for Main Oscillator

Hello Kuerbis,

The crystal oscillators that we generally see used with TM4C devices are the kind which provide a sine wave signal. The TM4C uses that to generate the system clock.

From what I have seen, the crystal oscillators which include a Tr/Tf spec are the kind that integrate the crystal plus the amplifier to output a single-ended clock.

That amplifier is integrated in the TM4C and so our datasheet specs are based on an external crystal only and the MCU handles the amplification and clock signal generation.

Kuerbis said:

Does this understand that if we meet the DCOSC_EXT specification based on Vih/Vil, we will not care about TR/TF?

I am not certain how accurate this is as really Tr/Tf isn't a spec that should be associated with an external crystal that produces a sine wave which is the basis for all the datasheet parameters.

Best Regards,

Ralph Jacobi