M9K Resource in SOPCB

Thanks dsl. I have a problem in understanding the Fitter result. Below describes my problem:-

result from quartus ii compilation:-

On-chip ram 1 – 27648 bytes

M9K Usage after Compilation - 32 M9K

On-chip ram 2 – 10200 bytes

M9K Usage after Compilation – 10 M9K

As far as I’m concerned, only power of 2 values of memory size are meaningful. Hence for on-chip ram 1, instead of 27648 bytes, 32768 (2^15) will be used. It makes sense that 32 M9Ks will be used according to

32 x (32-bit-wide x 256-word-deep)

However, for on-chop ram 2, could you please explain why Quartus II Fitter ends up with using only 10 M9K? I suppose it’s using 16 M9K because 16384 bytes (2^14) will be used instead of 10200 bytes.

If I further increase the memory size for on-chip ram 2 from 10200 bytes to 10500 bytes, the M9K usage for both on-chip ram 1 and on-chip ram 2 in Fitter report change even though I did not change the memory size for on-chip ram 1.

Here is the result:-

On-chip ram 1 – 27648 bytes

M9K Usage after Compilation – 28 M9K

On-chip ram 2 – 10500 bytes

M9K Usage after Compilation – 12 M9K

I have difficulty in understanding the behavior as to how the on-chip memory is forced into block size that maps well to 1k address depth increment for RAM performance optimization purpose.

Thanks,

Carid