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AR# 13837

5.1i CORE Generator asynchronous FIFO - I cannot choose the FIFO depth that is indicated in the data sheet


General Description:

In the data sheet for FIFOs, the following information is given regarding FIFO depth:

"...available depths are (2^N ?1). N can be any integer from 1 to 16, with additional restrictions based on the Data Width."

Why can I only select depths of 15 and higher in the CORE Generator GUI, when the lowest value should be 1?


This is an error in the data sheet -- it should read:

"N can be any integer from 4 to 16."

This means that the minimum depth is 15.

An Asynchronous FIFO depth of 15 is the physical minimum, due to the granularity of distributed LUT RAM. Even if an Asynchronous FIFO is created with a shallow depth, the same amount of resources would be used.
AR# 13837
Date Created 08/29/2007
Last Updated 05/27/2011
Status Archive
Type General Article