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Other Special Components

To complete the Calc design, add a STARTUP symbol so you can reset the logic.

The STARTUP Block (XC4000E/EX, XC5200 only)

The STARTUP block allows global control of different aspects of a design. In this example, STARTUP connects an external signal to the global set/reset net built into the XC4000E architecture. This global net connects to all flip-flops in the device and sets or resets them asynchronously. (Set or reset is determined at the flip-flop level.) Using this built-in resource provides the advantage of not wasting routing resources tying a system-wide reset signal to all flip-flops in the design. For more information on STARTUP, see the Libraries Guide.

The STARTUP symbol used here to implements a system-wide reset signal called NOTGBLRESET. This signal is active-low; therefore, when NOTGBLRESET is low, the Calc circuitry resets.

  1. In the Calc schematic, add the components, nets, and labels as shown in the illustration that follows. Take all the components from the XC4000E library.

    Figure 8.46 Adding the STARTUP Symbol

    The signal path gets an inverter because the GSR pin on STARTUP is active-high. Also, because GSR implicitly connects to all reset logic throughout the device, GBLRESET connects only to the GSR pin on the schematic.

  2. Check and save the Calc design.

Adding the Part Type to the Schematic

You can add the part type to the top-level schematic to pass on to the Design Manager.

  1. Double-click on the background of the top-level schematic sheet, or right-click and select Properties. The Schematic Properties dialog box appears.

  2. Under the Attributes tab, enter PART in the Name field and XC4003E-PC84-4 in the Value field.

    This specifies an XC4003E device with -4 speed grade (approximately 4 nanoseconds delay through a CLB) in an 84-pin PLCC.

    The PART value can take one of the following two formats.

    [XC]part_number-package-speed
    [XC]part_number-speed-package

    Therefore, the PART property can use all of the following legal values.

    XC4003E-PC84-4
    XC4003E-4-PC84
    4003E-PC84-4
    4003E-4-PC84

    NOTE

    If using a different device, type that device number into the Value field instead, for example, XC95108-PC84-10

  3. Click on Set, then OK. PART=XC4003E-PC84-4 appears in the lower left-hand corner of the schematic.

  4. Check and save the Calc schematic.

NOTE

Workview Office 7.2 and Powerview users must use the CONFIG symbol, as described here. The CONFIG symbol tells the place-and-route software how to process the design. In this example, the CONFIG symbol specifies the part number for this device.

To add the CONFIG symbol follow these steps.

  1. From the Calc schematic, call up the CONFIG symbol from the XC4000E library. Place this symbol in the lower right-hand corner of the Calc schematic.

  2. Double-click on the CONFIG symbol to add properties. Under the Attributes tab, enter the Name as “PART” and the Value as “XC4003E-PC84-4” and click OK.

  3. Place the property text within the confines of the CONFIG symbol, as shown in the following figure.

    Figure 8.47 Adding the CONFIG Symbol

  4. Check and save the Calc schematic.

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