Vampire 600 V1: Using FPGA Accelerator as Logic Analyzer
Posted on Thursday, August 23 2012 @ 13:27:08 CEST by majsta
Huge problem for me now is that I don't have any single one working Amiga 600 motherboard, so I had to repair one or two to be able to continue my work. For that job I need serious equipment that I didn't have until today. For proper repair it is not enough to just track schematics and change parts I had to "catch" signals to see it and find out what's wrong on the motherboard. For that job I needed Logic Analyzer so I created Logic Analyzer using my FPGA Accelerator board. 5 minutes job and now I have serious equipment.
1. Accelerator uses VCC from Amiga motherboard
2. JTAG -> USB connection to the PC
3. One probe from Accelerator
4. VHDL code (one part for translators, second one for probe , third for LED who depends on probe status)
UPDATE:
In process of using this Accelerator as Logic Analyzer I realize that there is huge problem because Accelerator don't have over voltage protection and every time I accidentally "touch" 12V on Amiga motherboard I destroy Voltage Level Translator. So I needed to have some over voltage protection and after some calculations I decided that best way is to add 680 OHM resistor on input probe to limit clamp current. Now everything is working perfect.