I’ve got the FPGAs on friday, but had no PLCC sockets to test them out. So I had to wait until the weekend passed by and the package from my local electronics (why do I feel the urge to write drugs, the parts are nearly that expensive) supplier arrived. The FPGAs I’ve received from a customer of ours are Atmel EMP7160S, getting programmed by a JTAG interface and the software from Atmel (Quartus II).
After everything was soldered in place and powered on my powersupply showed a current draw of 0.1 Amps so the circuit seemed to be consuming electrons. That was at 01:30 am.
The next day the FPGAs got programmed but since I had no spare oscillators I had to fetch some (you can place an order by phone or over the internet and collect them after two hours at the electronics suppliers place). After soldering the oscilator wrong twice (notice: the pins on the backside of a part appear to be mirrored ;-) and a coding simple frequency divider in VHDL I called it a day.
Fresh out of the HD an overview of the la:
32 Probes connected to four quad-input latches provide the input. The FPGA decides wheter or not to begin sampling.
If a trigger occurs the FPGA counts the addresses up on the A-Bus and drives the RAM to collect the data.
A PIC is used to communicate with the PC, setting trigger-masks and transfering the data measured.
Since the FPGA is a 84-pin PLCC-package I have about 60 input pins:
- 32 for the D-Bus
- 14 for the A-Bus
- ~9 for communicating
- 1 oscillator (GCLK1)
- 1 variable clock (freq-divider inside the FPGA)
This leaves me with 8 spare pins. Lets me think that I should really get me some thin wirewrap wires, the 0.22 mm^2 wire is just not suited to solder a piece with 84 pins ;-)
More to come…