LMK05318BEVM: ~100MHz PRIREF is declared invalid unless Late/Missing Detector is disabled

david royle

Part Number: LMK05318BEVM

If I increase the configured and supplied freq of PRIREF in steps, i.e. 25MHz then 50MHz then 80MHz then 90MHz then 100MHz I can get it to recognize 100MHz PRIREF.

However if I configure an supply 25MHz, then reconfigure and supply 99MHz or 100MHz. it indicates not valid. Tried soft chip reset then write all registers does not help.

Disabling Late/Missing Detector disabled is needed for it to declare valid.

According to datasheet (9.3.7.2.4), missing pulse detection should work up to (fVCO1)/12 = 2400MHz/12 = 208MHz.

over 3 years ago

0 Kia Rahbar over 3 years ago

TI__Expert 8585 points

Hello David,

Can you please provide me with your tcs file?

Regards,

Kia Rahbar

0 david royle over 3 years ago

Intellectual 565 points

Does not seem to depend on anything I am doing. This TCS file is just the default EVM configuration with the REFCLK1 changed to 100e6.

0 david royle over 3 years ago

Intellectual 565 points

I emailed the tcs file. There does not seem to be a way to attached it here

0 Kia Rahbar over 3 years ago in reply to david royle

TI__Expert 8585 points

Hello David,

When you change the reference frequency, the new reference frequency will not take effect until a run script is performed (as highlighted in the image below).

Please perform a run script and then observe the reference validity.

Also please ensure that the PRIREF_VALSTAT and SECREF_VALSTAT (highlighted in the image below) are used to observe the validity of the reference.

Regards,

Kia Rahbar

0 david royle over 3 years ago in reply to Kia Rahbar

Intellectual 565 points

I am running the script, and also doing soft reset and write all regs (which seems to be necessary after running script). PRIREF_VALSTAT is used to observe the validity.

0 Kia Rahbar over 3 years ago in reply to david royle

TI__Expert 8585 points

Hello David,

Please try enabling the frequency detect threshold and then observing to see if the reference is detected.

Regards,

Kia Rahbar

0 david royle over 3 years ago in reply to Kia Rahbar

Intellectual 565 points

Frequency detection works as advertised. What is not working is that at clean 100MHz reference (tried from two different sources) is not deemed valid unless Late/Missing is disabled.

0 Kia Rahbar over 3 years ago in reply to david royle

TI__Expert 8585 points

Hello David,

This appears to be some kind of bug in the software. I have informed the software team and they will look into solving this issue. Please proceed by disabling the late/missing window detector as you have been doing. The late/missing window detector is not required to be enabled for the device to function properly.

Regards,

Kia Rahbar

0 david royle over 3 years ago in reply to Kia Rahbar

Intellectual 565 points

Do you think this is a TicsPro bug, or a chip bug?

0 Kia Rahbar over 3 years ago in reply to david royle

TI__Expert 8585 points

Hello David,

This is a bug with TICS Pro. We have seen this issue previously and have always recommended to just disable the late/missing. Also, you were able to have the 100 MHz be detected with the late/missing enabled when you programmed the device in a different manner, thus indicating that the IC is operating properly. Sometimes when registers are not written in a specific manner, the TICS Pro software encounters issues due to bugs in its software. We have noticed these issues and are in the process of revamping our entire software in the coming months. Apologies for the difficulties.

Regards,

Kia Rahbar

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LMK05318BEVM: ~100MHz PRIREF is declared invalid unless Late/Missing Detector is disabled