Is VCCPD = 3.3V and VCCIO = 2.5V allowed on an Arria V?

Hi,

Short answer: No, VCCPD = 3.3 V with VCCIO = 2.5 V is not a supported combination for Arria V.

You need to ensure the compatibility between the VCCPD and VCCIO for an I/O bank. Refer here:

https://docs.altera.com/r/docs/683213/current/arria-v-device-handbook-volume-1-device-interfaces-and-integration/guideline-ensure-compatible-vccio-and-vccpd-voltage-in-the-same-bank

Below link is the supported VCCPD / VCCIO combinations for LVDS:

https://docs.altera.com/r/docs/683213/current/arria-v-device-handbook-volume-1-device-interfaces-and-integration/i/o-standards-voltage-levels-in-arria-v-devices

Notice that VCCPD = 3.3 V is not listed as a supported combination at all for banks with LVDS. The only supported VCCPD value for a 2.5 V VCCIO bank (with LVDS) is 2.5 V.

This is also consistent with the other I/O standards.

In another document, from the footnote 119, you can see the compatible combination VCCPD and VCCIO.

Recommended operating conditions for VCCPD

What you should do instead

Set VCCPD = 2.5 V for your 2.5 V VCCIO bank. This is the correct and documented combination for an I/O bank running 2.5 V LVCMOS and true LVDS.

For your JTAG interface at 3.3 V: the JTAG pins (TDI, TDO, TMS, TCK) on Arria V are powered by V_CCPD of the bank in which the pin resides. You may need to isolate this bank specifically only for configuration purposes.

Regards,

Aqid