These commands are used to report differential pair information from a PCB or Schematic design.
List Of Differential Pair Chains
Use at the top level to report information about each differential pair chain in a PCB or Schematic design, or use within a List of Nets command to report each chain that contains nodes on the net.
For each differential pair chain you can report the following:
- Chain Name - Reports the name of the differential pair chain.
- Min Percent Paired - Reports the percentage the two track paths are paired at the minimum gap distance.
- Maximum Pair Skew - Reports the maximum amount the two track paths are allowed to differ in length. This value is taken from the Differential Pair Skew Rule assigned to the chain.
- Has Track Spurs - use this to test if the chain has any track spurs in the two paths from start to end nodes.
- Is First Pair Line - This is only relevant when List of Differential Pair Chains is used within a List of Nets command. Use this to report if the current net is on the first pin pair side of the chain.
- Is Complete - Use this to report if both halves of the chain are fully routed between the pins.
- Pair Skew - Reports the difference in total track length between each of the pin pairs. This value can be compared with the Maximum Pair Skew value to see it is a fault.
- Paired Length - Reports the total length of track where the two halves of the chain are the required gap apart. Note, this length is the actual track lengths only and is not adjusted by any additional length factors.
- Percent Paired - Reports the Paired Length as a percentage of the total length of track between a pin pair. It will report the lower of these percentages for each half of the chain as this represents the worst case. Use this to compare against the Min Percent Paired value to report rule failures.
- List Of Differential Pairs - Use to report details about all of the differential pair links in the chain. See below for details.
- List Of Pin Pairs - Use to report each of the two pin pairs that make up each side of the chain. See below for details.
- List Of Rules - Use to report a description of all of the rules that are defined for the chain. See Rule Commands for more details.
- List Of Track Length Rules - Use to report the track length rule that is defined for the chain. See Rule Commands for more details.
- List Of Track Length Match Rules - Use to report the track length match rules that are defined for the chain. See Rule Commands for more details.
List Of Differential Pairs
Use at the top level to report information about each differential pair in a PCB or Schematic design, use within a List of Differential Pairs command to report all links in the chain, or use within a List of Nets command to report each signal path that contains nodes on the net.
For each differential pair you can report the following:
- Diff Pair Name - Reports the name of the differential pair.
- Net Name - Reports the name of the net the first pin pair is on.
- Second Net Name - Reports the name of the net the second pin pair is on.
- Allow Broadside Coupling - Will report true if the differential pair is allowed to have broadside coupled tracks.
- Allow Edge Coupling - Will report true if the differential pair is allowed to have the more normal edge coupled tracks.
- Allow Track Spurs - Will report true if the differential pair is allowed to have track spurs along its length to vias or other pins. It will report false if the differential pair can only have a single track path between its pins with no spurs.
- Min Gap - Reports the minimum distance the pair of tracks can be apart on any side. If the value is blank the track to track spacing will be used.
- Min Gap On Top Side - Reports the minimum distance the pair of tracks can be apart on the top side. If the value is blank the Min Gap value will be used.
- Min Gap On Bottom Side - Reports the minimum distance the pair of tracks can be apart on the bottom side. If the value is blank the Min Gap value will be used.
- Min Percent Paired - Reports the percentage the two track paths are paired at the minimum gap distance.
- Maximum Pair Skew - Reports the maximum amount the two track paths are allowed to differ in length. This value is taken from the Differential Pair Skew Rule assigned to the differential pair.
- Has Track Spurs - use this to test if the pair has any track spurs in the two paths from start to end nodes.
- Is First Pair Line - This is only relevant when List of Differential Pairs is used within a List of Nets command. Use this to report if the current net is on the first pin pair side of the differential pair.
- Is In Chain - Use this to report if the differential pair is a link in a differential pair chain.
- Is Complete - Use this to report if both halves of the pair are fully routed between the pins.
- Pair Skew - Reports the difference in total track length between each of the pin pairs. This value can be compared with the Maximum Pair Skew value to see it is a fault.
- Paired Length - Reports the total length of track where the two halves of the differential pair are the required gap apart. Note, this length is the actual track lengths only and is not adjusted by any additional length factors.
- Percent Paired - Reports the Paired Length as a percentage of the total length of track between a pin pair. It will report the lower of these percentages for each half of the differential pair as this represents the worst case. Use this to compare against the Min Percent Paired value to report rule failures.
- List Of Pin Pairs - Use to report each of the two pin pairs that make up the differential pair. See below for details.
- List Of Diff Pair Gaps - Use to report details about all of the Differential Pair Gap Rules that apply to this differential pair. See below for details.
- List Of Rules - Use to report a description of all of the rules that are defined for the differential pair. See Rule Commands for more details.
- List Of Track Length Rules - Use to report the track length rule that is defined for the differential pair. See Rule Commands for more details.
- List Of Track Length Match Rules - Use to report the track length match rules that are defined for the differential pair. See Rule Commands for more details.
List Of Diff Pair Gaps
Use within List of Differential Pairs to report all of the Differential Pair Gap Rules that are defined for the differential pair. Each gap rule defines the minimum distance a pair of tracks can be apart on particular layers or within named areas.
For each gap rule you can report the following:
- Attribute Name - The name of the attribute that defines the basis of the match criteria for the rule. A differential pair must have this attribute to use the rule.
- Match String - The wildcard string that is used to match the attribute value on a differential pair for it to use the rule.
- Rule Name - A combination of the Attribute Name and Match String, representing the name used for the rule.
- Rule Condition - Reports a description of the conditions for use of this rule, for example area name and layer name.
- Rule Values - Reports a string describing the values that apply for the rule to be satisfied on an item.
- Area Name - Reports the name of the area the rule will apply within, blank if no area involved.
- Layer Name - Reports the name of the track layer the rule will apply on, blank if no explicit layer defined.
- Side - Reports the side of the board the rule will apply on (Top, Outer, Inner or Bottom), blank if no side defined.
- Minimum Gap - The minimum gap will either be an actual numerical value, or
to specify that the track to track spacing rule for the layer and area will be used, or to specify that paired tracks are not allowed for the layer and area defined.
List Of Pin Pairs
Use within List of Differential Pairs and List of Differential Pair Chains to report both of the pin pairs representing each of the sides.
For each of the two pin pairs you can report the following:
- Start Node and End Node - Reports the names of the pads or branch points at the start and end of the pin pair.
- Net Name - Reports the name of the net the pin pair is on. Other standard net field commands are also available.
- Distance - Reports the Point to point distance between the two pins.
- Total Length - Reports the length of track in the path between the two pins, including estimated lengths for unrouted connections and applying length adjustments. See How the Lengths are Calculated for more information on adjusted lengths.
- Via Count - Reports the number of vias in the track path between the two pins.
- Has Track Spurs - use this to test if the pin pair has any track spurs in the path from start to end node.
- Is Track Length Adjusted - Reports “true” if the track length calculation has included any adjustments, otherwise reports “false”.
- Is Track Length Estimated - Reports “true” if the track length calculation has included the lengths of any unrouted connections, otherwise reports “false”.
- Minimum Pin To Pin Length and Maximum Pin To Pin Length - These commands are used within to report the min and max allowed pin to pin length values for the track path between the two pins. The values are extracted from the track length rules for the current net, sub net or signal path. These values can then be used to test against the pin pair Track Length field to report problems.
- Chain Links Count - Not used for a differential pair or chain. This command is used on a list of pin pairs on a net or sub net, see See Track Length help page for more details.
- Is Complete - Use this to report if there is a fully routed path between the pins.
- Is Differential pair - This is used elsewhere, it is always true for pin pairs in differential pairs or chains.
- Is Selected - Use this to report if either of the pins is selected in the design.
- Paired Length - Reports the length of track between the two pins where the tracks are the required gap apart from the other half of the differential pair.
- Percent Paired - Reports the Paired Length as a percentage of the total length of the tracks between the two pins.
Example use of Differential Pair List
List Of Differential Pairs
List Of Pin Pairs
Net Name
Start Node - Node Name
End Node - Node Name
Is Complete
Track Length
Paired Length
Percent Paired
Blank Line
Min Percent Paired
Percent Paired
Max Pair Skew
Pair Skew
Text "Min Gaps:"
List Of Diff Pair Gaps
if "Layer Name" is blank
Side
Else
Layer Name
Area Name
Min Gap
2 Blank Lines
The report output looks like this:
A1POS C1.1 C2.1 True 519.9 286.0 55.01%
A1NEG C1.2 C2.2 False 418.9 286.0 68.28%
Min % Paired: 98.00% 55.01%
Max Pair Skew: 101.0
Min Gaps:
Side: All Gap: 50
D5POS C3.2 C5.2 True 622.1 497.7 88.00%
D5NEG C4.1 C6.1 True 621.3 497.0 88.00%
Min % Paired: 88.00%
Max Pair Skew: 100.0 0.3
Min Gaps:
Layer: Top Gap: 45.0
Layer: Bottom Gap: 21.0
Side: All Gap: <Spacing Rule>
Related Topics
Commands | Differential Pairs | Report Maker | Rule Commands