Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

Cyclone V LVDS & DDR3 on same bank

Hello, I am planning to use a Cyclone V 5CGTFD7D5F31 with the following requirements; - 32 bit DDR3 interface Top and Bottom (64 bit total) - 68 LVDS input p...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

--- Quote Start ---

So, assuming that the LVDS input buffers are powered from VCCPD = 2.5V, can I use the LVDS differential inputs if VCCIO is set to 1.5V fro DDR3?

Also, can I use RD OCT?

If not, can I do it with external RD?

--- Quote End ---

The lvds input rd oct paragraph states clearly that Rd OCT requires 2.5 VCCIO. So external 100 ohm termination resistors are required. The statement suggests in return, that the combination VCCPD=2.5, VCCIO < 2.5V (e.g. 1.5 V) is possible. Did you check, if Quartus V11.1 accepts LVDS receivers in a 1.5 V bank?