Simple counter divider VHDL Example

FPGA: XC5202 PC84

VHDL FILE: divx84.vhd

SYNTHESIS TOOL: XILINX/ALDEC Foundation Software

XILINX RBT FILE: divx84.rbt

XILINX PROM FILE: divx84.mcs (not needed but available)

C Code Real Time Control File: divtst.cpp

C Development Platform: Borland C++ 5.0

EXAMPLE DESCRIPTION:

This example blinks the APS-X84 on board LEDs at programmable rates. The 5202 bit file is downloaded via the PC bus to configure the FPGA. The X84 boards DONE LED shows that the FPGA was configured correctly. The C program handles the download. It then prompts the user to type in the divide value, which the FPGA takes in and uses to divide the output of the X84 on board 555 timer circuit. This example is a great way to show how to set up an address and data bus on the FPGA , to allow it to accept commands. The VHDL code shows how to do a basic counter which counts the output pulses of the 555 and sends the divided value to the X84 on board LEDs. It shows how to configure the FPGA from the PC using C code and the .rbt files produced by the XILINX XACT software. Although this is a simple VHDL program it covers much in the way of interfacing and control, and is a great introduction to several topics. Using the X84 schematics (provided with the X84 board kits) engineers get to see the details of implementing the download via the PC BUS or via the PROM or XCHECKER cable. [INFORMATION REQUEST]