Intelligent Design Runs Next Steps - 2025.2 English - UG906

Incorporating IDR Results into a Main Project Run

1. Right-click the top-level IDR.
2. Choose one of the following:
   • Generate Single Pass Implementation Run to create an equivalent run to the IDR that replicates the best run results with greater compile-time efficiency. The structure of this run is dynamic and depends on:
     • QoR suggestions that improved the design
     • Implementation command directives from either the Stage 1 implementation or the Stage 2 ML-predicted strategies, depending on which produced the best run
     • An additional Tcl procedure added after route_design if Stage 3 (Last Mile) produced the best results

     This run is most useful for reproducing results with the same input netlist, such as closing out a timing-closed build. It can perform poorly with design changes, and including Last Mile can increase compile time.

   • Generate ML Strategy Runs to create three implementation runs using the top three ML-predicted implementation strategies, including any QoR suggestions that improved the design. This approach is generally better for design iterations because it excludes Last Mile, which adds extra compile time.

If you later need to add Last Mile to an ML strategy run, you can use the Last Mile script on a fully routed DCP file.

Running the Last Mile Script

The Last Mile script is supported in AMD Vivado™ 2023.1 and later for Versal, AMD UltraScale+™ , and AMD UltraScale™ devices. It runs intensive algorithms to close timing on a fully routed design and can be called manually or added as a TCL_POST hook after phys_opt_design -directive Explore.

1. Open a fully routed design in Vivado.
2. Confirm that the design meets the entry criteria:
   • QoR Assessment score of 3 or greater
   • WNS of at least –0.250
3. Generate QoR suggestions for the Last Mile flow.
4. Enable any incremental-friendly QoR suggestions found.
5. Run Last Mile optimization commands:
   • phys_opt_design with clock, retiming, and LUT optimizations
   • place_design -directive LastMile
   • Additional phys_opt_design and route_design commands with the Explore directive
6. Optionally write intermediate or final checkpoints and timing reports.

Tcl Implementation

package require Vivado 1.2022.1

namespace eval ::xilinx::designutils {
    namespace export last_mile
}

proc ::xilinx::designutils::last_mile {{write_intermediate_files 0} {write_final_files 0}} {
# Vivado   : Supported 2023.1 and later
#
# Families : Versal, Ultrascale+, Ultrascale
#
# Summary  : Run last mile flow. This is equivalent to 
#            running stage 3 in IDR.
#            The last mile flow will run intensive 
#            algorithms trying to close out timing 
#            on a fully routed design.
#            It is recommended to run post route 
#            phys_opt_design -directive Explore before 
#            running last mile.
#            A call to this script can be added as a 
#            TCL_POST hook to post route 
#            phys_opt_design -directive Explore.
#          
#            The requirements to run this are:
#              i)   A fully routed open design
#              ii)  When called a check will be made to
#                   see if the QoR Assessment Score of 3 
#                   or 4 is achieved, if not it will exit.
#              iii) A WNS >= -0.250
#
# Arguments:
#
# write_intermediate_files - 
# When set to 1, writes out intermediate DCP and timing 
# reports after:
#  i)   preplace phys_opt_design, 
#  ii)  place_design
#  iii) postplace phys_opt_design
#
# write_final_files - 
# Writes reports and DCPs after the final stage 
# route_design 
# when set to 1.
#  Project users:     It is recommended to leverage 
#                     project infrastructure to write 
#                     reports
#  Non-Project users: Recommended to add custom 
#                     write_checkpoint and reporting 
#                     commands after this script is 
#                     executed.
#
# Return Value:
# 1 - last mile completed successfully
#
# Categories: xilinxtclstore, designutils
set top [get_property TOP [current_design]]

# Entry Checks
puts "-I: Checking last mile entry criteria is met..."
if {[llength [current_design -quiet]] == 0} {
	puts "-E: Last mile requires an open design that is\
	fully routed"
	return -code 2 "Error: Last mile requires an open\
	design that is fully routed"
}
if {[report_route_status -boolean_check ROUTED_FULLY] == 0} {
	puts "-E: Last mile requires a design that is fully\
	routed"
	return -code 2 "Error: Last mile requires a design\
	that is fully routed"
}
# actual value is 3
if {[set score [get_assessment_score]] < 3} {
	puts "-E: Last mile requires a design has an QoR\
	Assessment Score of 3 or greater.\
	Design Score: $score"
	return -code 2 "Error: Last mile requires a design\
	has an QoR Assessment Score of 3 or greater.\
	Design Score: $score"
}
# actual value is -0.250
if {[set slack [get_property SLACK [get_timing_paths -setup]]] < -0.250} {
	puts "-E: Last mile requires a design a WNS >= -0.250\
	Design Slack: $slack"
	return -code 2 "Error: Last mile requires a design a\
	WNS >= -0.250. Design Slack: $slack"
}
puts "-I: Passed last mile entry criteria checks"

# QoR Suggestion Generation
puts "-I: Generating QoR Suggestions for Last Mile"
report_qor_suggestions -file ${top}_qor_suggestions_lastmile.rpt
if {[llength [get_qor_suggestions -filter {INCR_FRIENDLY} -quiet ] ] > 0} {
	puts "-I: Enabling generated incremental friendly\
	QoR Suggestions..."
	write_qor_suggestions -of_objects \
	[get_qor_suggestions -filter {INCR_FRIENDLY}] \
	-force -file ${top}_qor_suggestions_lastmile.rqs
	set_property ENABLED 1 [get_qor_suggestions \
	-filter {INCR_FRIENDLY}]
} else {
	puts "-I: No QoR Suggestions found for last mile\
	flow. Flow will continue.."
}

# Tool Flow Commands
phys_opt_design -clock_opt -retime -lut_opt
if {$write_intermediate_files != 0} {
	report_timing_summary -delay_type min_max \
	-report_unconstrained -check_timing_verbose \
	-max_paths 10 \
	-input_pins -routable_nets \
	-rpx ${top}_timing_lastmile_preplace_physopt.rpx \
	-file ${top}_timing_lastmile_preplace_physopt.rpt
	write_checkpoint -force \
	${top}_lastmile_preplace_physopt.dcp
}	
place_design -directive LastMile
if {$write_intermediate_files != 0} {
	report_timing_summary -delay_type min_max \
	-report_unconstrained \
	-check_timing_verbose \
	-max_paths 10 \
	-input_pins \
	-routable_nets \
	-rpx ${top}_timing_lastmile_placed.rpx \
	-file ${top}_timing_lastmile_placed.rpt
	write_checkpoint -force \
	${top}_lastmile_placed.dcp
}
phys_opt_design -directive Explore
if {$write_intermediate_files != 0} {
	report_timing_summary -delay_type min_max \
	-report_unconstrained \
	-check_timing_verbose \
	-max_paths 10 \
	-input_pins \
	-routable_nets \
	-rpx ${top}_timing_lastmile_postplace_physopt.rpx \
	-file ${top}_timing_lastmile_postplace_physopt.rpt
	write_checkpoint -force \
	${top}_lastmile_postplace_physopt.dcp
}	
route_design -directive Explore
if {$write_final_files != 0} {	
	report_timing_summary -delay_type min_max \
	-report_unconstrained -check_timing_verbose \
	-max_paths 10 -input_pins -routable_nets \
	-rpx ${top}_timing_lastmile_routed.rpx \
	-file ${top}_timing_lastmile_routed.rpt
	write_checkpoint -force \
	${top}_lastmile_routed.dcp
}
phys_opt_design -directive Explore
phys_opt_design -directive Explore
if {$write_final_files != 0} {	
	report_timing_summary -delay_type min_max \
	-report_unconstrained -check_timing_verbose \
	-max_paths 10 -input_pins -routable_nets \
	-rpx ${top}_timing_lastmile_postroute_physopt.rpx \
	-file ${top}_timing_lastmile_postroute_physopt.rpt
	write_checkpoint -force \
	${top}_lastmile_postroute_physopt.dcp
}

return 1
}