ERF Variables for Signal Layer Checks

Variables set in the ERF file control the analysis.

ERF Variable

Description

Categories Affected

classify_pad_ar

Determines how via or PTH measurements are reported.

yes — Classify AR measurement according to via or PTH in ‘Via Annular Ring’ or ‘PTH (Comp) Annular Ring’. (default)

no — Report all via or PTH measurements in ‘PTH Annular Ring’.

PTH Annular Ring

PTH (Comp) Annular Ring

Blind Via Annular Ring

Buried Via Annular Ring

classify_pad2pad

no — All measurements reported to ‘Pad to Pad’ category. (default)

yes — Distributes measurements to the following categories, depending on pad type:

  • ‘Toeprint to Toeprint’ — when both pads belong to the same component with attribute Required Toeprint Spacing.

  • ‘SMD to SMD’ — When both pads are SMD pads.

  • ‘Via to Via’ — When both pads are pierced by a via drill.

  • ‘PTH to PTH’ — When both pads are pierced by a non-via drill.

  • ‘Pad to Pad’ — All other pads.

Via to Via

Pad to Pad

classify_via2c

0 — Do not distinguish between via and PTH measurements to copper. Report both in ‘PTH to Copper’. (default)

1 — Distinguish between via and PTH holes. Report measurements in ‘Via to Copper’ or ‘PTH to Copper’.

PTH to Copper

PTH to Copper Same Net

Via to Copper

group_drill_to_copper

Determines whether to report only the closest violation or all violations.

1 — For each drill (NPTH, PTH, or via) only the closest spacing violation is reported to its respective category. If there are both pad and circuit spacing violates with NPTHs, only the closest is reported in its respective category (either ‘NPTH to Pad’ or ‘NPTH to Circuit’). The category of the other violation does not appear. (default)

0 — All spacing violations are reported, each to its respective category.

NPTH to Pad

NPTH to Circuit

PTH to Copper

PTH to Copper Same Net

Via to Copper

large_net_min

Nets with more than large_net_min features are ignored in ‘Same Net Spacing’, ‘Sliver’ and ‘Short Sliver’ categories.

Same Net Spacing

Sliver

Short Sliver

len2width_ratio

Minimum ratio of length to width of a line to be inserted in the ‘Lines’ category.

Lines

limited_npth_check

Determines whether NPTH annular ring values larger than pp_d2c are reported.

yes — Only distances less than pp_d2c are reported. (default)

no — All values reported.

NPTH Annular Ring

max_bottleneck_width

Maximum bottleneck width for ‘Conductor Width’ and ‘Copper Bottleneck’.

Conductor Width

max_line_width

Maximum line width in ‘Lines’ category.

Lines

Line Neckdown

Arc

max_reg

Maximum offset to be considered a registration error. A center to center distance of a drill and pad larger than this value, is not reported.

PTH Registration

NPTH Registration

min_line_len

Minimum line length in ‘Lines’ category. Also the minimum overlap between lines to report in parallel spacing.

Lines

Spacing

pth_breakout_angle

Defines maximum angle allowed for breakout of drill from PTH pad.

PTH Annular Ring

PTH (Comp) Annular Ring

reg_allowance

A distance between pad center and drill center greater than this value is considered misregistered.

PTH Registration

NPTH Registration

replace_crosshatch_by_surface

Determines how slivers are reported.

yes — Do not report slivers found on hatched area. (default) (Gerber)

no — Report slivers found on hatched area.

by attr — Do not report slivers found on features with a hatch attribute. (EDA)

Sliver

Short Sliver

report_lines_with_arcs

Determines how lines with arcs are reported.

yes — Arc sizes are reported to ‘Lines’ or ‘Shaved Line’. (default)

no — Arc sizes are reported in ‘Arcs’ or ‘Shaved Arcs’.

Lines

Shaved Line

Arc

Shaved Arc

rm_d2c

Reliability margin for all drill to copper measurements other than annular ring. Used in the calculation of the DRA attributes.

Affects the reporting of result attributes for drill categories

self_spacing

Determines whether self-spacing measurements are taken.

yes — Self-spacing measurements are taken. (default)

no — Self-spacing measurements are not taken.

Same Net Spacing (Spacing)

Same Net Spacing (Bottleneck)

spacing_length_measure

Determines whether parallel spacing measurements are taken.

yes — Parallel spacing measurements are taken. (default)

no — Measurements are not taken.

Spacing Length

spacing_resolution

Determines the resolution for parallel spacing report. (1mil = default)

Spacing Length

v_bottleneck_algorithm_mode

Defines which of two algorithms is used to determine bottleneck violations.

0 — Use original algorithm where results are reported to ‘Conductor Width’ (Bottleneck) and ‘Same Net Spacing’ (Bottleneck). (slow)

1 — Use improved algorithm where results are reported to ‘Copper Bottleneck’ (Bottleneck). (default) (fast)

2 — Results are the same as with 1, but the process is slower. (Remains in the system to insure backward compatibility.)

Conductor Width (Bottleneck)

Same Net Spacing (Bottleneck)

v_conductor_width_full_check

Determines how conductor width is checked.

no — Conductor width is not checked if a line or arc is touched by more than a certain, threshold, number of negative shapes (neckdowns). The result is better performance. (default)

yes — Conductor width is checked, no matter the number of negative shapes. Therefore, there is a degradation in performance.

Conductor Width

v_dist2sliver_ratio

Minimal ratio for the distance between measurement segment endpoints along the net and the width of the sliver.

See “DFM Analysis Compatibility for Signal Layer Checks

Sliver

Short Sliver

v_min_sliver_len

Slivers shorter than this value are reported as ‘Short Sliver’. All others are reported in ‘Sliver’. Maximum possible value is 100 mils.

See “DFM Analysis Compatibility for Signal Layer Checks

Sliver

Short Sliver

v_min_sliver_perim

Defines the minimal distance between the measurement segment endpoints along the net. (For a description of perimeter, see “Sliver and Short Sliver Categories (Signal Layer Checks)”).

Sliver

Short Sliver

v_report_via_by_type

Determines whether via annular ring violations are reported to ‘Via Annular Ring’ or to individual categories according to via type.

no — Report all via annular ring violations to ‘Via Annular Ring’. (default)

yes — Report via annular ring violations according to type: regular, blind or buried.

Blind Via Annular Ring

Buried Via Annular Ring

v_sliver_algorithm_mode

Defines which of two algorithms is used to determine sliver violations.

0 — Use original algorithm where results are reported to the ‘Sliver’ category. (slow)

1 — Use improved algorithm where results are reported to either the ‘Sliver’ or ‘Short Sliver’ category. (fast) (default)

2 — Results are the same as with 1, but the process is slower. (Remains in the system to insure backward compatibility.)

Sliver

Short Sliver

v_slivers_check_diff_nets

no — Do not report slivers detected between unconnected features (on different nets). (default)

yes — Report slivers detected between unconnected features, and distances between close nets.

See “DFM Analysis Compatibility for Signal Layer Checks

Short Sliver

v_split_pth2c_report

Determines whether to report results from the same CAD net in this category along with those of different CAD nets or to ‘PTH to Copper Same Net’.

no - report all results to this category. (default)

yes - report same CAD net results to ‘PTH to Copper Same Net’.

PTH to Copper

PTH to Copper Same Net

v_stubs_check_both_ends

yes — Lines and arcs with both ends touching the same surface or feature are reported as stubs. (default)

no — Ignore stubs touching the same surface or feature.

Stubs

v_surface_spacing_separately

Determines whether measurements to surfaces are reported as circuits or into their own categories.

no — Report surfaces as circuits to categories ‘Circuit to Circuit’, ‘Pad to Circuit’ and ‘NPTH to Circuit’. (default)

yes — Report measurements to surfaces to ‘Surface to Surface’, ‘Pad to Surface’, ‘Circuit to Surface’ and ‘NPTH to Surface.’

Pad to Circuit

NPTH to Circuit

v_terminated_stub

Determines whether lines with small pads at their endpoints are reported as stubs.

0 — Do not report such lines as a stub.

1 — Report lines with a pad smaller than the line endpoint (and having the same x and y coordinate) as a stub. (default)

2 — Report lines with a pad smaller than or equal to the line endpoint as a stub.

Stubs

v_tp_exvia_as_via

Determines whether an exposed via with attribute ICT Test Point is considered a via (reported in ‘Exposed Via to Exposed Via’) or a copper pad (reported in ‘Exposed to Exposed’).

no — Consider via pad with attribute ICT Test Point a copper pad. (default)

yes —Consider via pad with attribute ICT Test Point a via.

Exposed Via to Exposed Via

Exposed Via to Exposed Copper

via_breakout_angle

Defines maximum angle allowed for breakout of drill from via pad.

PTH Annular Ring

Blind Via Annular Ring

Buried Via Annular Ring