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  3. AR# 4244: Leonardo: How to change the slew rate from Leonardo.(Fast, Nodelay)

AR# 4244

Leonardo: How to change the slew rate from Leonardo.(Fast, Nodelay)

説明

Keywords: Leonardo, Exemplar, slew, rate, fast, nodelay

Urgency: Standard

General Description:
Leonardo currently defaults all outputs with the slew rate set
to FAST. The following describes how to change the slew rates

ソリューション

1

To set an output port with a FAST slew rate:
set_attribute -port <portname> -name FAST

To set all other output ports with a SLOW slew rate:
set xlx_fast_slew FALSE

Internal Note: Using M1.4 with Leonardo 4.2, one can not
change the slew rate to slow via the ucf file

2

Leonardo also default input register to NODELAY.
Here is how you can set a port with delay in Leonardo.
Say, the signal going from ibuf to IFD is called data_in.
After doing a 'READ' you can then do:

set_attribute -port data_in -name DELAY -value TRUE

Then do 'Optimize', 'WRITE', M1 etc.

Also you can specify the instance of the IFD if it is
instantiated, or also the net name.

set_attribute -instance my_ifd -name DELAY -value TRUE

or
set_attribute -net net_name -name DELAY -value TRUE.

You should also be able to specify the medium delay if needed
... MEDDELAY.
AR# 4244
日付 10/05/2008
ステータス アーカイブ
種類 一般