7 Segment Display Using Xilinx XC95108 CPLD Board

Apr 19, 2007 1 Replies

Im working on a project and I need some help so if you have any experience in this subject matter i dont mind that you speak your mind with your ideas. I greatly appreciate it.


7 Segment Display Using Xilinx XC95108 CPLD Board


As shown in the class, a CPLD board used in our laboratory has been used to display a counter output. This project is asking you to use your knowledge in the ELEN 327 course and the experience you accumulated in ELEN 328 to design a circuit, which is able to drive the display on the Xilinx XC95108 CPLD board and show the exact demonstration.



Things that concerned:


  1. Design a counter that counts the cycle of even decimal numbers only, starting from 0, 2, 4, ... to 20 and restarts from 0 again. You can use any kind of flip-flop circuits, such as D-type, T-type, or JK flip-flop.
  2. Design a decoder, which decodes the output of a binary counter, and translate it into a seven segment driver. Since the counter starts from 0, ends at 20 and starts from 0 again, you need two 7-segment display to show it. The actual pin connection information about these two 7-segment display is at the end of your laboratory book.
  3. Clock divider, which uses the high-speed crystal oscillator as the source. The frequency of the crystal oscillator on our CPLD board is

4 MHz. You need to reduce this frequency in order for our eyes to identify the counter output. You can also call this clock divider as a speed controller. If you adjust the speed right, this display can be a normal wall clock.

The block diagram of this design is shown below:



Crystal Oscillator------->Clock Divider------>Even Counter--------



Binary Counter Decoder-------->7-Segment Display

It looks like you have all of the specs for the project. A XC95108 CPLD is certainly large enough for the project. Xilinx's WebPack ISE will allow you to enter your design as 1) a schematic, 2)VHDL HDL, and

3) Verilog HDL. There are examples of counters and 7-seg display drivers all over the 'net. So, get going!

-Dave Pollum

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