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AR# 35757

Distributed Memory Generator v4.1/4.2/4.3 - why does distributed RAM not have the same write mode settings as block RAM?

Description

Block RAM has three settings for write mode:

  • read-first
  • write-first
  • no change

Why does distributed RAM not have the same settings for write mode?
If data input and address are put into distributed RAM simultaneously, what contents do I get back?
What is the latency of the read operation?

Solution

The read operation of distributed ram is asynchronous, which is why it does not have the same settings for write mode as block RAM.

If data input and address are sent to distributed RAM simultaneously, you will get previous stored data first, then it will read out newly written data.

If Distributed Memory Generator output is not registered, the output will be read out when the address is available.

AR# 35757
Date Created 05/18/2010
Last Updated 10/20/2016
Status Active
Type General Article
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