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AR# 20093

6.3is1 PAR - "ERROR:Place:120 - There were not enough sites to place all selected components"

Description

Keywords: DSP48, XtremeDSP Slice, filters, columns

When using the XtremeDSP Slices in a cascade up a column in a device, you might encounter the following message in PAR when the cascade becomes the same size as the length of the column:

"ERROR:Place:120 - There were not enough sites to place all selected components"

For example, the LX25 is 48 XtremeDSP Slices tall. The column lengths differ for each device; see (Xilinx Answer 20851) for detailed information.

Solution

1

To resolve this issue, the PAR implementation tools need to be directed to place the first DSP48 in lowest placed DSP48 site location in the device. This can be done by applying the following LOC constraint to the first XtremeDSP Slice in the chain, as shown in the following example:

INST "M00_MADD1" LOC = "DSP48_X0Y0" ;

These LOC constraints are typically added in the constraints file (.ucf).

2

If you are using System Generator for DSP as a design entry tool, you must still use the LOC constraint resolution detailed above to work around the problem. This must be done in the ISE design environment.
AR# 20093
Date Created 09/03/2007
Last Updated 09/04/2008
Status Archive
Type General Article