Frequency meter? So simple you may say. Yes, sure. But doing FPGA based frequency meter that can be instantly used by thousands of of engineers? Hm.. once long time ago I did a JTAG controlled in FPGA Frequency meter IP Core and PC GUI application for it also. I think I wanted to have some pictures and links to Xilinx and yes I did got at least semi-official "green" from them to-do so. The GUI application talked over LPT Based JTAG adapter and did some clever tricks to measure the frequency on some FPGA pin without the use of any known reference clock in the FPGA. As part of that work I did get from semi-official channels schematic of original Xilinx Parallel Cable IV. In order to support it I did create a Coolrunner JEDEC to VHDL conversion tool. I also had a ideas about integration with Chipscope IP Cores, so I did some reverse engineering on the Chipscope ICON.
This was long time ago.
LPT Ports are long past history, so bringing back in live that old design makes no sense. Maybe the use for all FPGA based simple Frequency counter is already done? There are options of course, Altium has on-chip instrumentation that includes Frequency meter (if I recall it correctly). But Altium FPGA support is something that is maybe fun for educational purposes not much usable for real life.
Vivado Labtools do not have Frequency meter.
Who said that? They do now!
Here, TE0710 Art ix module as hardware test bench. Frequency Counter IP Core configured for 4 channels. Reference clock is from 100 MHz oscillator. Just for testing 33.3333 MHz and 800MHz signals from FPGA Clock PLL are connected to channels 0 and 1. Channels 2 and 3 are connected to I/O Oscillator IP Core. Channel 2 I/O pin is "empty" FPGA ball from DDR3 bank with 1.5V I/O Voltage. Channel 3 I/O pin is in 1.8V bank and is connected to on-board Ufl coaxial connector with PCB trace of about 12 mm length.
Overview
Content Tools