New Users Forum

[bhavin@ti]

After FPGA is programmed, I need to change IOSTANDARD for pin, without reprogramming FPGA? Is there any way to do it?

[eteam00]

I do not know if partial reconfiguration is an option for IOSTANDARD configuration.  If not, then you will need to re-synthesise and the configuration data will change.

-- Bob Elkind

[mcgett]

You are designing to a fixed board and the iOSTANDARD should not need to be changed.  Why do you think that you need to change the IOSTANDARD?

[austin]

Yes,

Partial reconfiguration may be used for this purpose.  In the past, I have seen customers make two (or more) different bitstreams, and use the 'diff' command to find the IO standard configuration bits, and then use ICAP to rewrite just those frames that need to be changed, with just those bits (to change the IO standards).  The IOframes are kept in a BRAM, which is used as a ROM, or look up table.  You look up what IO standard you want, and you load just those frames (you store the frame numbers with the frames, so you know which ones to load).

I have seen this used to program a board in a system, when the system does not know how many loads a board must drive, until the entire system;'s needs are determined (by a "roll-call" after power is applied).

It is not as fancy as a partial reconfiguration design, as only the IO frames need to be rewritten, and this may be done while everything is running, and will not disturb anything.