Answers Database XC2000: Considerations when Migrating an XC2000 Design to a Newer Device Family Record #3115 Product Family: Hardware Product Line: 2000 Product Part: 2000 Problem Title: XC2000: Considerations when Migrating an XC2000 Design to a Newer Device Family Problem Description: Urgency: Standard General Description: The following are considerations to be aware of when                 attempting to migrate from an existing XC2000 device                 to a newer FPGA device. Solution 1: Usually the easiest migration path from an XC2000 to a newer device family is just to print out all of the schematics and re-enter the design. If the original design was performed on a design entry tool which allows for an easy migration path to a newer existing design entry tool then by all means, this should be done but many XC2000 designs were either created within Xilinx Design Editor (XDE) or an out-dated design entry tool. The biggest XC2000 device was an XC2064 and that stands for 64 CLBs (each containing 1 Function Generator and one FF). This means that such a design typically is not too large and design re-entry is typically not be that encompassing of a task. During the design migration, the following should be considered: 1. XC2000 have asynchronous SET and RESET on each FF. None of our other      FPGA devices have this feature. If this design happens to use an      asynchronous set and reset, one would have to be converted to a      synchronous signal. 2. Pin compatibility. If it is required to stay in the same device package,      most of the pinouts could be preserved but it is possible that not all      of the pinouts can remain unchanged. 3. If the design is originated from a schematic, the design is most      likely originally created in pre-unified libraries. These would      need to be interpreted into unified equivalents. 4. Asynchronous paths in the design's timing will change. This needs      to be accounted for. 5. If the design uses external crystal, XC5200 and XC4000 do not have      XTL1 and XTL2 crystal amplifier pins. It is suggested to go to a      canned oscillator. 6. XC5200 and XC4000 do not have PWRDWN pin. If the design is using this      suggest to use the GTS signal instead. 7. A timing simulation is highly suggested after the design conversion to      ensure that functionality did not change and that the design will run      properly at system clocking speeds. End of Record #3115 - Last Modified: 02/01/99 16:03

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