CycloneV :MSEL(4:0) and VCCPGM voltage

Hi @HBhat2-GRL​

You are correct. VCCPGM for 2.5V and below is not supported for AS mode. I stand corrected for my previous answer.

I found a kdb that explains it:

https://www.intel.com/content/altera-www/global/en_us/index/support/support-resources/knowledge-base/solutions/rd04262013_77.html

Hope this clears all the doubts.

As per all the Intel recommendation documents, VCCPGM must be 3V/3.3V for AS x1, ASx4 configuration.

I am not sure why it is 2.5V in Cyclone V SoC kit. But, in Cyclone V GX Dev kit, VCCPGM is 2.5V, but no support for ASx1 and ASx4 mode.

Regards,

HPB

Hi @AGofs​

If you refer to https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/dp/cyclone-v/pcg-01014.pdf

It states that: Connect these pins to either a 1.8V, 2.5V, 3.0V, or 3.3V power supply

Thus, it is ok for VCCPGM to connect to 2.5V.

The RS and RP external resistors is to give an effective 100 ohm differential output impedance

Thank you ,JwChin for answer about "CycloneV :MSEL(4:0) and VCCPGM voltage" issue!

The issue is clear.

Does your last answer "The RS and RP external resistors is to give an effective 100 ohm differential output impedance" is connected to this issue or to another?