In UltraScale and UltraScale+ devices, there
is no RESET_AFTER_RECONFIG
option. Instead, GSR is
always issued at the end of a partial reconfiguration, and there are no Pblock
size/shape requirements to enable this like there are in 7 series devices. However, to ensure that the
Pblock does not violate any rules for minimum PU sizes, the SNAPPING_MODE
property is also always on by default, and automatically
adjusts the Pblock to make sure it is valid for PR.
The following figures provide an example of how SNAPPING_MODE
adjusts the Pblock for PU alignment. Despite the larger
outer rectangle, only the selected tiles belong to the RP Pblock. The upper block RAM
and DSP sites are not included because they are not fully contained in the Pblock, and
the associated CLB sites are not included either, based on the PU rules. There are also
CLB sites on both the left and right edge that are not included in the Pblock because
the adjacent CLBs are not owned by the original rectangle.
While SNAPPING_MODE
made the above
Pblock legal for the RP, it is possible that the intent was to include all of these
sites. By making a small adjustment to the original Pblock rectangle, you can prevent
SNAPPING_MODE
from removing sites that are intended
for the dynamic region. The Pblock has been expanded by one CLB on the left, right, and
top edges. The shaded tiles that are owned by the RP Pblock now match the outer
rectangle.
While shading shows what is included in a reconfigurable partition (RP),
you can best visualize the sites owned by an RP by using the get_dfx_footprint
utility. The following steps can be used for
debugging/verifying Pblocks:
- Create or make an adjustment to an RP. The cell assigned to the
Pblock must have the
HD.RECONFIGURABLE
property set. - Use the
get_dfx_footprint
utility to see the placement tiles for a given pblock.highlight_objects -color <color> [get_dfx_footprint -place -of_objects [get_cells <RP_cell>]]
Note:Theget_dfx_footprint
Tcl utility is available for UltraScale and UltraScale+ devices and is a much more powerful and efficient visualization tool compared to hd_visual scripts. For more information onget_dfx_footprint
, see Floorplanning Visualization. Versal has expanded capabilities for DFX as compared to UltraScale and UltraScale+, so the options that are available to UltraScale and UltraScale+ devices are limited to the following:-
-place
: placement footprint of a reconfigurable Pblock -
-route
: routing footprint of a reconfigurable Pblock -
-illegal_nodes
: set of nodes that cannot be used for an RP
-