Noob question, Is the changover for XTALIN Automatic for CY7C68013A-100?

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
StMa_4556336
Level 1
Level 1

Hi All

Hopefully this isn't covered elsewhere, but I've spent some time searching and had no luck.

I have a device with a 24MHz xtal and would like to change this to an external 3.3v oscillator.  I notice from the manual that XTALIN doubles up as an xtal input and external 3.3v square wave clock.

My question is this:  Can I simply remove the 24MHz xtal and capacitors and connect an external clock to XTALIN with no firmware mods?  Does the pin function change automatically?

Thanks for reading.....

Steve

0 Likes
1 Solution
Sananya_14
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi Steve,

Yes, the external 24 MHz clock can be connected directly to XTALIN pin with XTALOUT unconnected and firmware change is not required.

Please refer to the App Note for the external clock requirements.

Best Regards,

Sananya

View solution in original post

0 Likes
2 Replies
Sananya_14
Moderator
Moderator
Moderator
750 replies posted 500 replies posted 250 solutions authored

Hi Steve,

Yes, the external 24 MHz clock can be connected directly to XTALIN pin with XTALOUT unconnected and firmware change is not required.

Please refer to the App Note for the external clock requirements.

Best Regards,

Sananya

0 Likes

Hi Sananya

Thank you for your helpful reply and link to the app note.  I have a logic analyser based on the above chip with an Altera Cyclone IV FPGA.  I'm pretty sure the FPGA is clocked from the Cypress chip/xtal so I'd like to change the xtal to a 3.3v txco for better accuarcy in the logic anlyser measurements.

Have a good day......

Steve

0 Likes