I'm using an Arria V SOC device with more than 17Mbits of on-chip RAM.
My design requires using a Dual Port RAM of the following dimensions:
Width - 64 bits.
Depth - 32,000 (64 bit words).
This gives a total memory content of ~2Mbits (well within the 17Mbits budget).
Yet when I compile the design, I get the following fitter error:
Error (170039): Cannot place 256 RAM cells or portions of RAM cells in the design
As far as I understand
Why can't the tool partition the memory across its RAM resources ?
Note: I'm using Quartus 14.1
That error message tells user that it needs 256 block of memory where it is insufficient. Are you assigning partition to that memory block or any module? Try to enlarge the region size.
The memory size calculation needed is not just base on as simple as width x depth. It depends on the configuration on certain memory block, eg M20K ,MLAB or M10K https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/hb/arria-v/av_52002.pdf, Table 2-6.