about clock gating for multiple blocks

Ah. That solution is not very good, timing wise.

A better way to do it is either to use ATLCLKCTRL blocks to gate the clocks or to use clock enables instead of gated clocks.

However, using ALTCLKCTRL only works if your device has enough clock networks.

Since you have quite a few blocks, you'll most likely want to use clock enables (or a mix of gated clocks and clock enables).

I recommend you take a look at this thread: http://www.alteraforum.com/forum/showthread.php?t=2388