Get email delivery of the Cadence blog featured here
It's here! It's really here!!!
I've spoken with many customers over the past several years and so many have requested an automatic Table of Contents (TOC) generator for Allegro Design Entry HDL (DEHDL).
In most of the designs you construct, the first sheet (or sheets) of the schematic design contain a table of contents (TOC). The SPB16.2 release contains the functionality for creating and automatically updating a TOC with design information. The automatic TOC generator feature saves you design time since it does not require any manual validation.
The information displayed in a TOC can range from sheet specific data such as sheet number, sheet name, module or block name to design specific data such as project name, engineer, date, total number of pages, and so on. The TOC also helps in navigating the design when the schematic designs are plotted or published which provides an aid for the engineers reviewing the design.
In order to include a TOC in your design, you need to instantiate the TOC symbol in your schematic. Typically, a TOC symbol includes predefined custom text variables for sheet specific data, such as:
- sheet number (CON_TOC_SNO)- sheet name (CON_TOC_SNM),- block name (CON_TOC_BNM).
Allegro Design Entry HDL evaluates these variables at run time. You can add custom text variables for design specific data, such as project name, engineer, date, total number of pages, etc. to the default TOC symbols.
You can instantiate a TOC symbol on a schematic sheet just as you instantiate any other symbol. To add a TOC symbol to a schematic design, the following steps are required:
1. Open the design. The names of all the sheets appear in the Hierarchy Viewer.
2. Select a page in hierarchy viewer. Page titles are derived from a property in the page border and displayed in the Hierarchy Viewer. This property can be specified/configured in the Setup (Tools> Options> Design Navigation). Also, you can modify this property in the Attributes form.
3. Right click the page border and choose Attribute. The sheet name is mentioned as the TITLE property on the page border. The property from which the sheet name can be selected.
4. Insert one sheet before page 1. A new page is inserted before page 1.
5. Place the TOC symbol on this sheet:
a. Select page 1 in the Hierarchy Viewer. b. Choose Component > Add. c. Select Standard from the list of libraries. d. Select toc. 'toc' is the name of the TOC symbol used in the sample design. You can select any other custom TOC symbol. e. Select toc in the Search results tab. f. Click the Add button. g. Click on page 1. h. Right click and choose Done from the pop-up menu.
6. Choose File> Save.
7. Click a page in Hierarchy Viewer (other than page 1) and then click page 1 again. The TOC symbol will be generated.
Some VERY COOL features of the automatic TOC:
Creating Custom TOC Symbols:
You can also create custom TOC symbols for your design. For example, you can enhance the Page Border symbol and use it as a TOC symbol. You can use lines (wires) to draw tables and place logo bitmaps on the symbols. The TOC symbol is identified by the property TOC_SYMBOL set to TRUE.
Steps involved in this process:
1. Select a sheet with a page border in hierarchy viewer.
2. Double-click on the page border and open the symbol.
3. Save the symbol as a TOC symbol.
4. Choose Text> Custom Text.
5. In the Custom Text dialog box, select CON_TOC_SNO as the custom text and specify the Repeat count. Repeat count decides the number of entries for the custom text in the TOC symbol.Tip: There a shortcut to align the added TOC properties. Place one property, then type “Copy N” where N is the repeated number of properties to place. Then select the TOC property and place the copied property below. The space between the original and new property will be be repeated for the remainder of the new properties.
6. Click on the symbol origin to attach the custom text. Now the custom text variable shows a linkage with the symbol origin.
7. Place the custom text variable on the top left part of the sheet. According to the Repeat factor selected in the Custom Text dialog box, the custom text entries are added to the symbol one below the other.
8. Similarly, you can add the CON_TOC_SNM and CON_TOC_BNM custom variables to the TOC symbol.Tip: Ensure that you have all the three columns horizontally aligned. Keep enough space for the sheet names, as they are usually long.9. When you have finished adding the custom variables, you might want to add some more graphics, such as rectangles or boxes created using wires around the TOC or even add a bitmap, if required.
10. Set the TOC_SYMBOL property to TRUE and attach it to the origin of the symbol:
a. Choose Text> Attributes. b. Trace and click the origin of the symbol. c. Click Add on the Attributes form. d. Type TOC_SYMBOL in the Name column. e. Specify TRUE as the value
11. Choose File> Save to save the symbol. You can now instantiate this symbol in a schematic:
a. In the schematic, insert a new sheet before sheet 2. The sheet opens with the default page border. b. Replace the page border with the TOC symbol. c. Choose File> Save to save the design. d. Select any other page from the hierarchy viewer and then move back to the newly added TOC page.
As always, I"m interested in how you're using this TOC capability and if you have any suggestions on how we can improve the capability.
Hi Charlie! Good to see your comments here. Could you elaborate a bit more on the absence of an Index? What structure/format would you like to see?
We've looked at and plan to use the new TOC capability. We have been using our own internal solution for a number of years, but will abandon it in favor of the Cadence provided solution, if we deem it to have met all of our internal requirements. It offers a clear advantage over our implementation in the fact that it updates dynamically whereas our solution must be run explicitly to update the TOC. The only known shortcoming todate is the absence of an Index. We have communicated this request to R&D. We're awaiting a response.