RAM_STYLE - RAM_STYLE - 2026.1 English - UG901

RAM_STYLE instructs the Vivado synthesis tool on how to infer memory. Accepted values are:

block

Instructs the tool to infer RAMB-type components.

distributed

Instructs the tool to infer the LUT RAMs.

registers

Instructs the tool to infer registers instead of RAMs.

ultra

Instructs the tool to use the AMD UltraScale+™ URAM primitives.

mixed

Instructs the tool to infer a combination of RAM types designed to minimize the amount of space that is unused.

auto

Lets the synthesis tool decide how to implement the RAM. XPMs mainly use this value to choose a value for RAM_STYLE. This is the same as the default behavior. That must choose a value for RAM_STYLE.

By default, the tool selects which RAM to infer based on heuristics that give the best results for most designs. Place this attribute on the array declared for the RAM or a hierarchy level.

• If set on a signal, the attribute affects that specific signal.
• If set on a hierarchy level, this affects all the RAMs in that level of hierarchy. This does not affect the sub-levels of the hierarchy.

You can set this in RTL or XDC.