RAM_DECOMP - 2022.1 English

Vivado Design Suite User Guide: Synthesis (UG901)

Document ID
Release Date
2022.1 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 2K x 36 would often be configured as two 2K x 18 BRAMs arranged side by side. This is the configuration that yields the fastest design. By setting RAM_DECOMP, the RAM would instead be configured as 2 1K x 36 BRAMs. 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 then 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.