03-31-2011 11:19 AM
I have just received my CoolRunner-II CPLD starter kit and see that the clock source installed is limited to 1MHz.
I would like the CPLD to run much faster in a data acquisition application.
I have a Epson 66.67000 (MHZ?) crystal from a Xilinx XC3S1600E (Digilent) board in the 4 pin DIP package. Can I use this crystal on the CoolRunner board.
Thanks for any help
03-31-2011 01:07 PM
When you say you've got a "crystal" in a 4-pin DIP, do you mean a crystal oscillator?
There is a 4-pad (SMT, not thru-hole) pad pattern labeled "IC4" on the back of the
starter kit board. According to the schematics the pinout is:
1 OE - (output enable) tied directly to 3.3V
3 OUT - (LVCMOS clock output) signal XCCLK to CPLD pin 32
4 VDD - +3.3V
You should check your oscillator for compatibility with this pin configuration. The
frequency should be no problem.
03-31-2011 02:11 PM
Thanks for answering.
The board is the CoolRunner-II CPLD Starter Kit with the oscillator socket IC3 on the front of the card.
I checked the Spartan3e board circuit diagram against the Starter kit and it actually seems to be the same part, so I should be good ( I should have done this anyway before posting the first time).
03-31-2011 02:14 PM
That's the problem with just saying "the CoolRunner II Starter Kit" - there's more than
one board that's been called that. Mine is the "X" board (actually shaped like an "X")
but is has pretty much the same features.
04-01-2011 07:56 AM
On a slighty related note, the DVD in the paskage for ISE 11.1 was faulty - this does not seem to be that unusual from reported problems.
Luckily I had version 8.2 of the IDE which seems to work fine until I get somewhere with a fast internet connection and can download a more recent version in reasonable times.
04-01-2011 08:08 AM
I don't think there are major changes between your 8.2 and the most recent
versions of ISE when it comes to the CoolRunner II series. Most of the recent
updates are focused on the new FPGA families. There may be some improvements
in XST for synthesis, but given the amount of code you can fit in a 256 macrocell
CPLD, it isn't likely to be of great benefit. By the way when I got my CR2 kit, they
were shipping the ISE 9.1 DVD.
If you're going to eventually do the download, I'd suggest getting the 12.x tools
because they're much more stable than the 13.1 release and the ISIM
simulator is improved over the 11.x tools. If you already have ModelSim
or other tools for simulation, then you may not see much difference from
the 11.x tools.