How to use an osciloscope with a FPGA using Vhdl

Question

Any of you have any material about this?

I want to show an std_logic_vector(0 to 29) on the osciloscope

Answer 1

That's 30 bits ... you don't want to probe 30 pins.

I'd use 2 spare pins and roll a simple serial interface off a suitable (eg 1 MHz) clock and a /32 counter.

One pin shifts out each bit according to the count, the other is set when you send the first bit, as a convenient triggering signal.

Either let it free run, or tell it to start (inside the FPGA) every time you update that signal.

Answer 2

Most FPGA vendors provide some kind of in-system debugger (like ChipScope for Xilinx ISE designs). These provide a very powerful debugging perspective for your FPGA design and allow you to record waveforms on hundreds of signals.