RAM_DECOMP - 2023.2 English

Vivado Design Suite User Guide: Synthesis (UG901)

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2023.2 English

The RAM_DECOMP attribute instructs the tool to infer RTL RAMs that are too large to fit in a single block RAM primitive to use a more power-friendly configuration.

For example, a RAM specified as 2 K x 36 would often be configured as two 2 K x 18 block RAMs arranged side by side. This is the configuration that yields the fastest design. By setting RAM_DECOMP, the RAM would instead be configured as two 1 K x 36 block RAMs. This is more power-friendly because during a read or write, only the one RAM with the address being used is active. It comes at the cost of timing because Vivado synthesis must use address decoding. The RAM_DECOMP would force the second configuration of that RAM.

The value accepted for RAM_DECOMP is "power".

This attribute can be set in either RTL or XDC. Place the attribute on the RAM instance itself.