What's Good About Capture Intersheet References? The Secret's in the SPB16.3 Release!

The SPB16.3 release of OrCAD Capture now allows you to create intersheet references on flat designs, simple designs, and complex hierarchical designs. Design navigation in Capture now also includes a signal navigation feature to navigate through the connected signals on a design. This feature allows you to select a signal that you want to trace and then browse through all the connected signals on the design.

Intersheet references indicate the source and destination of schematic page and schematic signals in the design, making it easier to trace signals and find errors in the electrical connectivity of the design. An intersheet reference for an input signal indicates all the schematic pages from which the signal originates. An intersheet reference for an output signals indicates all the schematic pages to which the signal goes.

For example, an output hierarchical port with intersheet references 6, 8, and 10 indicate that the signal goes to schematic pages 6, 8, and 10.

Read on for more details…

Intersheet references in a flat design

For every off-page connector on the pages of a flat design, the intersheet reference of its port will be attached to that connector. Note the off-page connectors (A, B and C) attached to the parts across the three pages in the screenshot below. Notice the output if you create intersheet references to trace the signals across the pages of this design:

Connector A: Since the three connectors lie on Page 1, the intersheet references are defined as 1 for A connectors.

Connector B: On Page 1 the reference is defined as 2,3. This implies that the signals for this connector exist on Page 2 and Page 3. Similarly, you see the Connector B reference on Page 2 is 1, 3 and the reference on Page 3 is 1,2.

Connector C: The Page 2 reference for Connector C is 2,3 since the signals exist on Page2 and 3. Now the Page 3 reference for both Connector C connectors on Page 2 and 3 show as 2,3. This implies a signal exists on Page 2.

 
Intersheet references in a hierarchical design

For every pin that is present on a hierarchical block, the intersheet reference of its port will be attached to that pin. Take the example of the FULLADDER design that contains two occurrences of the HALFADD hierarchical blocks (see below). Note that the hierarchical blocks on the FULLADD page are connected to the two HALFADD pages via hierarchical ports. Notice the output if you create intersheet references to trace the signals across the pages of this design:



CARRY_IN (FULLADD): The intersheet reference for the CARRY_IN port on the FULLADD page is defined as 2!. This implies that the signal for this port is on page two of the design (halfadd_A). Also, the exclamation (!) symbol implies that the connected signal exists one level lower in the hierarchy.

X (FULLADD): The reference for the X port on the FULLADD page is defined as 3!. This indicates that the connecting signal is on page 3 (halfadd_A). The exclamation symbol implies that the connecting signal exists one level lower in the hierarchy.

X (halfadd_A): The intersheet reference for the X port on the halfadd_A page is defined as 1^. This indicates that the connected signal exists on page 1 (FULLADD). Also, the caret (^) symbol implies that the connecting signal exists one level higher in the hierarchy.

Y (halfadd_A): The reference for the Y port on the halfadd_A page 1^,3 defines that one connecting signal exists on page 1 (FULLADD) and the caret symbol indicates that this signal exists one level higher in the hierarchy. The second connecting symbol exists on page 3 (halfadd_B). Similarly, the intersheet reference for the SUM port on the halfadd_B page is 1^,2.

Creating Intrasheet references

1. From the Tools menu, choose Intersheet Reference.
The Intersheet References dialog box displays:

         
You can also access this dialog box by choosing the Annotate option on the Tools menu. Then in the Annotate dialog box select the Add Intersheet References option and click OK.

2. Select the Place On Off-Page Connectors option if you want the intersheet references placed on off-page connectors.

3. Verify that the value used for X Offset is correct. This option adjusts the horizontal spacing between the port name and the intersheet reference.

4. Select or clear the option in the Port Type Match Matrix group box as necessary to specify how port types are to match each other when creating intersheet references.

5. Click OK. Capture performs error checking on your design while it generates intersheet references.

6. To generate a report of the interesheet references of the selected design, select the View Report option and specify the name of a CSV file in which you want to create the report.

CSV file generated for Intersheet References

The following report file sample is generated from the FULLADD design:

Description of the columns below for the generated IREF Report:

Name is the name of the port or off-page connector.

Type is the signal type.

Page defines the page on which the port or off-page connector exists.

Page Number are the page numbers as defined by the Page.

Number property of the title block on that respective page.

Schematic is the schematic folder containing the specific pages.

PartPin is the part and pin combination connected to the port or off-page connector.

LocationX is the X-axis location on the schematic page grid of the port or off-page connector.

LocationY is the Y-axis location on the schematic page grid of the port or off-page connector.

Zone is the zone location on the schematic page grid of the port or off-page connector.

 

Please share your experiences with this new Capture feature.

Jerry "GenPart" Grzenia