Spartan® Family FPGAs

[xiaochh]

   Hello,Everyone. We know that there are 32  Block RAM Blocks of 18Kbits in spartan 6LX-16.

   But I don't understand that why the bram resource is divided to RAMB16BWERs and RAMB8BWERs  after Synthesized , in one of my ip .xrpt file , the Specific Feature Utilization: is as follows:

Number of RAMB16BWERs	2	32	6%
Number of RAMB8BWERs	2	64	3%

   And in the total design design summary ,the bram resource  is :

                            Number of Block RAM/FIFO:               24  out of     96    25% 

   But the total bram is 32, if it is used as two independent 9 Kb ，it is 64 . Why here in the summary it is 96 ?

   If The 32 RAMB16BWERs  and the 64 RAMB8BWERs are different resource applyed ?

  Thanks ,Sincerely!

[barriet · Accepted solution]

The 16/18Kb BRAMs can each be fractured into 2 8/9Kb BRAMs. I suspect they are broken out like this to give you better visibility into their usage.

But you are correct - they should not be totaled - it is an either/or situation not both.

This appears to be a bug in the reporting scheme.

bt

[xiaochh]

Thanks, timpe ,your information is very important for my project.

 :smileyhappy: