731 - Lattice ispLEVER: How do I set up the VREF pins for use with the IOs?
Lattice ispLEVER: To set up a device's VREF pins using ispLEVER:
- Start up DESIGN PLANNER.
- In Design Planner, select VIEW, SPREADSHEET VIEW.
- In Spreadsheet View, select PREFERENCE, VREF LOCATIONS...
- In the Vref Setting window, enter a name in the VREF NAME dialog box and then left click on a pin in a bank for that reference name to assign to.
- Push the ADD button.
- Repeat for all the banks you want to assign VREF pins to.
- Close the VREF SETTING window.
- In the Spreadsheet View right hand window, for an input pin that you want to set a VREF voltage for, first go to the IO_TYPE column and select an IO type that can use the VREF voltage such as SSTL18_I.
- In the VREF column for that same pin, click on the cell to select the VREF reference voltage it should use. Note that DQS signals must use a VREF1 pin as VREF1 uses a special divider for DQS signaling.
- Repeat for all the IO pins that will be using the VREF input voltages.
- Save and exit from Design Planner. The VREF pins should now be assigned and the other IOs can use them as necessary.