Hi all,
New here. I'm new to the BBv4, but not new to the FT2232H nor JTAG usage.
I received my BBv4. The FTDI drivers (windows 7 and 10; 64bits) installed fine, and I can talk to the FTDI FT2232H IC (Using old TCL files that I had written based on FTDI's JTAG API and programming guides/examples). I can even read the device ID of the XC2C64A-VQ100, when I set the jumper to "buffer mode" on the BBv4, and communicate through channel 1 of the FT2232H (From TCL CLI).
So I know the FTDI IC and connections are fine. When I toggle TCK, on both channels 0 or 1 (A or B) on the FT2232H I can see the TCK pin/signal toggle on the scope, when I probe it. Probing the TCK traces that go into the Xilinx XC2C64A-VQ100, also shows the toggle. However, when I probe the output TCK pin out of the XC2C64A-VQ100, I get nothing. The TCK (and other JTAG signals) going into the XC2C64A-VQ100 don't come out at all. And yes the 3V3 jumper is set.
So, the question is, is the BBv4 shipped with a functional buffer? Does it ship with a jtagkey-clone buffer already loaded on the XC2C64A-VQ100?
I have followed the scattered info around. I can detect/svf on the modified version of urJTAG. But other than that, I can't find any info about what to load, if anything at all!
Any help would be greatly appreciated.
Thx
I am in no way a Bus Blaster expert, but my Bus Blaster v4 seems to work just as well as my v3. In my case I had to make sure to remove JP4 (Target Power).
I'm using OpenOCD 0.9.0 with the ftdi/dp_busblaster.cfg (JTAGkey, basically) for both.