Forum Discussion
Occasional ContributorCyclone V nCEO pin , what VCCIO when used as IO pin
Hello Simon,
The operating voltage for the configuration input pin is independent of the I/O banks power supply,
VCCIO, during configuration. You may refer on page 246 of Cyclone V Device Handbook from this link: https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-v/cv_5v2.pdfThe nCEO pin will comply with Table 15 from page 19 of that Cyclone V Device Datasheet when it is configured as general purpose I/O pin. Thus, the Vih value will depends on the I/O standard you set.
You are safe to put 3.3V of Vih to nCEO if you set 3.0-V LVTTL as I/O standard as situation you previously mentioned because the value of Vih can go up to 3.6V in that particular I/O standard.
Hope this clarifies.
Occasional ContributorHi and thank you for getting back to me.
For final clarification, as I may have inadvertently confused things...
If the nCEO pin is configured as general purpose IO it will comply to its bank VCCIO which is 3V3.
I can therefore safely feed a signal with a Vih of 3V3 into the nCEO pin.
Best regards
Simon
Regular ContributorHello Simon,
The operating voltage for the configuration input pin is independent of the I/O banks power supply,
VCCIO, during configuration. You may refer on page 246 of Cyclone V Device Handbook from this link: https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/cyclone-v/cv_5v2.pdf
The nCEO pin will comply with Table 15 from page 19 of that Cyclone V Device Datasheet when it is configured as general purpose I/O pin. Thus, the Vih value will depends on the I/O standard you set.
You are safe to put 3.3V of Vih to nCEO if you set 3.0-V LVTTL as I/O standard as situation you previously mentioned because the value of Vih can go up to 3.6V in that particular I/O standard.
Hope this clarifies.
