How this works
Blocks = ceil(requested width / primitive width) × ceil(requested depth / primitive depth). Unused bits = allocated capacity − payload capacity.
FPGA selection / T009
Estimate the block-count lower bound for a legal memory primitive configuration.
01 / DEFINE THE REQUIREMENT
02 / REVIEW THE OUTPUT
Ready for an example run. Check the inputs, then run the tool.
Block-count lower bound and unused bit capacity
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03 / METHOD & VERIFICATION
Method version 1 · 2026-09-27
FPGA.io planning aid. Arithmetic and checklist output do not replace device documentation, a design tool or engineering approval.
Blocks = ceil(requested width / primitive width) × ceil(requested depth / primitive depth). Unused bits = allocated capacity − payload capacity.
Widths 1–1,000,000 bits; depths 1–1,000,000,000 words; exact-integer limit enforced. Supply a legal vendor primitive mode for the chosen port arrangement.
36 × 1024 payload with an 18 × 1024 primitive mode → 2 blocks, 0 unused bits.
Use the example inputs to inspect how the method behaves. This is a reference calculation, not a hardware test.
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Report a method or input issue →04 / CONTINUE THE TASK
Keep exact device and board revisions with the assumptions you just checked.