What is the actual Maximum Frequency supported by DDR3 in the Cyclone5 GT device?

Hi Susmita,

I am sorry if my earlier reply does not fully address your query. Please refer to my reply below:

1)

a) I am still not clear about the answer. As you said GT device maximum frequency is 400MHz, but is this the maximum frequency of the DDR memory or the DDR 3 memory controller?

[Aida]: It is the operating frequency of the memory interface.

b) If I am using the DDR controller at half rate, will the AFI clock frequency be half of 400 mhz?

I wanted to know the maximum frequency of the controller which deals with RTl side/ user code.

[Aida]: Yes, you are right. If the DDR_CK is 400 MHz, then the AFI_CK will be 200 MHz at half rate.

2) yes, I cannot cross the maximum frequency, but i meant to ask that, if 150 Mhz is maximum frequency for instance, then is it safe to use the maximum value or should consider something like 135 or 140 mhz. Will the functionality hamper if I use the maximum value of 150 mhz?

[Aida]: This is really depend on your design. As long you can get clean timing, then I don't see any problem using lower/maximum frequency. From my experienced so far, I don't see any functionality effect when using maximum frequency.

Hope this helps.

Thanks

Regards,

Aida