Hi.

It uses an FPGA (or CPLD) and a clock (DS1075) for time reference. The
parts that i'm using a

Xilinx XC4010XL-PC84

Dallas DS1075-100

The FPGA has everything, it has 1 sec reference using the DS1075 (working at
100Khz), 5 divisors to select range of measurement, display control and
parallel port control.

There are two ways to improve it, one is that I can use the internal FPGA
oscillator, but it has a poor precision, and the other it's to use a
different oscillator, maybe a crystal oscillator.. it can be of any
frequency because that is programmable to the FPGA... that way it would be 1
IC frequency meter.

I will put it the VHDL source in the web with a hand-made schematic, and the
PC software. The VHDL can be synthetized with Xilinx Webpack (free download
from www.xilinx.com) and to program the FPGA you can use Xilinx Parallel
Cable III(schematics for it searching on www.google.com). You can use any
FPGA that has enough room to all the circuits, but I think the software can
suggest you wich one to use.

All of that can be found at

http://www.geocities.com/hernan_sanchez/

I will put the files there this night (3:00 GMT).

Regards,



Hernán Sánchez




"SWbeginner" escribió en el mensaje
...
"Hernán Sánchez" wrote in
:

Hi.

I have just designed one that uses 2 chips, it is controlled by a PC
(parallel port) and it has a software to display measurements.

It works from 1Hz to 80Mhz, and can be improved.. if you want to give
it a try, write me and I will send you the schematics and the software
to play with it. I have one working in a XESS FPGA card, but it
doesn't need all those hardware, just 2 of them.

Regards,

Hernán Sánchez
Sure I like to see it. Which 2 chips does it use?