RW_ADDR_COLLISION - 2024.1 English

Vivado Design Suite User Guide: Synthesis (UG901)

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2024.1 English

The RW_ADDR_COLLISION attribute is for specific types of RAMs. When RAM is a simple dual port, and the read address is registered, Vivado synthesis infers a block RAM and sets the write mode to WRITE_FIRST for best timing. Also, if a design writes to the same address it is reading from, the RAM output is unpredictable. RW_ADDR_COLLISION overrides this behavior.

The values for RW_ADDR_COLLISION are:

The default behavior as described previously.
These inserts bypass logic so that when an address is read from the same time it is written to, the value of the input is seen on the output making the whole array behave as WRITE_FIRST.
This is when you do not care about timing or the collision possibility. In this case, the write mode is set to NO_CHANGE , resulting in power savings.

RW_ADDR_COLLISION is supported in RTL only.