ucs_setup_tree_fix

Usage Guide — Multi-Corner Setup Tree Delay Cell Fix (Perl)

Script	ucs_setup_tree_fix
Version	UCS-1.0.0
Modified	2026-03-26
Purpose	Merge per-corner setup-tree slack/margin JSON records, select legal delay cells, and generate ECO Tcl
Environment	Standalone Perl (packaged executable), RHEL7 / RHEL8
Support	tech@universalchipstudio.com

Quick Nav: Features Quick Start Published Paths Options Fix Modes Output Examples

Key Features

Multi-Corner Merging — Accepts multiple per-corner setup-tree point JSON files and merges them into a unified view. Each point’s margin is computed across all corners to ensure the fix is legal everywhere.
Cell Delay Map Lookup — Reads one or more cell delay map files and selects the best legal delay cell for each tree point based on the merged margin requirement.
Three Fix Modes — conservative (use raw lendable margin only), balance (average of required and lendable), and aggressive (unlimited lendable). Guardband control via --current_margin and --next_guardband.
Iterative Solving — Each tree point is solved iteratively (up to --max_repeat rounds) to find the best matching delay cell that satisfies the merged margin constraint.
Preferred Cell Selection — Optional --prefer_cells restricts candidates to a subset of the delay map, allowing the user to bias toward known-good cells.

Quick Start

# Minimal: merge 3 corners and fix with default conservative mode
ucs_setup_tree_fix \
    --point_json corner_ss.json corner_ff.json corner_tt.json \
    --cell_delay cell_delay_map.txt

# Balance mode with guardband
ucs_setup_tree_fix \
    --point_json corner_ss.json corner_ff.json \
    --cell_delay delay_a.map delay_b.map \
    --fix_mode balance \
    --next_guardband 5.0 \
    --output eco_tree_fix.tcl

Published Paths

Location	Path
Source	`verified/sta/setup/perl_modular/bin/ucs_setup_tree_fix.pl`
RHEL7 executable	`publish/redhat7/sta/setup/perl_modular/bin/ucs_setup_tree_fix`
RHEL8 executable	`publish/redhat8/sta/setup/perl_modular/bin/ucs_setup_tree_fix`

Options

Required

Option	Type	Description
`--point_json`	string(s)	One or more setup-tree point JSON files. Each file contains per-corner slack/margin records for tree points. required repeatable
`--cell_delay`	string(s)	One or more cell delay map files. All files are merged in the given order. required repeatable

Fix Control

Option	Type	Default	Description
`--prefer_cells`	string(s)	—	Optional preferred cell list. When set, only cells present in both the delay map and this list are used as candidates. repeatable
`--fix_mode`	string	conservative	Fix policy: `conservative`, `balance`, or `aggressive`. See Fix Modes section below.
`--current_margin`	float	0	Extra delay added onto current-level required slack. Widens the fix target.
`--next_guardband`	float	0	Guardband reserved for the next level, subtracted from downstream available margin.
`--max_repeat`	integer	20	Maximum iterative solving rounds per tree point.

Output

Option	Type	Default	Description
`--output`	string	setup_tree_fix.eco.tcl	Output ECO Tcl file path.
`--eco_prefix`	string	ucs_setup_tree_fix	ECO naming prefix used inside the generated Tcl.
`--dump_failed`	string	—	Optional output file for unresolved points (JSON-ish text dump).

Information

Option	Type	Description
`--help`, `-h`	flag	Show help and exit.
`--version`	flag	Show version and exit.

Fix Modes

The fix mode controls how much margin is available for delay cell insertion at each tree point. The core formula is:

raw_lendable = next_margin - next_guardband
final_target = min(required, lendable)

Mode	Lendable Computation	Use When
`conservative`	`lendable = raw_lendable`	Default. Uses only the actual available downstream margin. Safest for production.
`balance`	`lendable = avg(required, raw_lendable)`	Compromise between required target and available margin. Good for moderate risk tolerance.
`aggressive`	`lendable = 9999`	Ignore downstream margin limits. Maximum fix coverage at the cost of potential downstream violations.

Guardband interaction: --current_margin adds to the required slack at the current level (makes the fix target larger), while --next_guardband subtracts from the available downstream margin (makes the lendable smaller). Together they control the safety margin of the fix.

Output Files

File	Content
`<output>` (default: `setup_tree_fix.eco.tcl`)	ECO Tcl commands to swap delay cells at resolved tree points
`<dump_failed>` (optional)	JSON dump of unresolved tree points with their merged margins

The script also prints a summary to stdout:

ECO file path written
Number of fixed points
Number of failed (unresolved) points

Usage Examples

Conservative Fix (Default)

ucs_setup_tree_fix \
    --point_json ss_tree.json ff_tree.json tt_tree.json \
    --cell_delay cell_delay_map.txt

Merge 3 corners, fix using conservative mode with no guardband.

Balance Mode with Guardband

ucs_setup_tree_fix \
    --point_json ss_tree.json ff_tree.json \
    --cell_delay delay_a.map delay_b.map \
    --fix_mode balance \
    --current_margin 2.0 \
    --next_guardband 5.0 \
    --output my_tree_fix.tcl

Use balance mode with 2ps current margin and 5ps next-level guardband.

Aggressive with Preferred Cells

ucs_setup_tree_fix \
    --point_json corner_a.json corner_b.json \
    --cell_delay full_delay_map.txt \
    --prefer_cells DELBUF_X1 DELBUF_X2 DELBUF_X4 \
    --fix_mode aggressive \
    --output aggressive_fix.tcl \
    --dump_failed unresolved.json

Aggressive fix using only preferred cells. Dump unresolved points for analysis.

Multiple Delay Maps with Custom Prefix

ucs_setup_tree_fix \
    --point_json tree_points.json \
    --cell_delay map_v1.txt map_v2.txt map_override.txt \
    --eco_prefix my_project_tree_fix \
    --max_repeat 50

Merge 3 cell delay maps (later files take precedence). Increase iteration limit to 50 rounds.