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AR# 39033

FIFO Generator v6.2/v7.2 - GUI will not preserve the "Depth" and "Programmable Flags" settings when the Implementation Type is changed from BRAM to Dist RAM or SRL 16's


FIFO Generator GUI will not preserve the "Depth" and "Programmable Flags" setting when the FIFO Implementation type is changed from Block RAM to any other type (i.e. Distributive RAM , Shift Register). Changing the Implementation type will reset to default value.


1. FIFO Implementation -> Block RAM
2. Depth -> 512
3. Programmable Flags -> "Single Programmable Full Threshold Constant" and "Single Programmable Empty Threshold Constant"
4. Change FIFO Implementation -> Distributed RAM
a. Depth -> reverts to 1024 default value
b. Programmable Flags -> "No Programmable Full Threshold" and "No Programmable Empty Threshold" default value


This is a known issue. The default range value gets reset whenever you select the Implementation option.

FIFO Generator GUI will not preserve the "Depth" and "Programmable Flags" settings when customer changes the Implementation Type from BRAM to Dist RAM or SRL 16's.


If the customer has chosen Block Ram implementation, and then selects "Depth" to any value other than default 1024, and then sets "Programmable Flags" to anything other than "No Programmable Full Threshold", and then decides to change the implementation type from Block RAM to either SRL 16 or Dist RAM, then the "Depth" and "Programmable Flags" will revert to default.

For the desired operation of the core, it is recommended to re-enter the initial settings after the implementation option selection.
AR# 39033
Date 12/15/2012
Status Active
Type General Article
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