LPC2148 JTAG Issues

Development Boards MicroMod
1

I’ve received the parts and assembled my first LPC2148 based design. Thanks to all of those who offered help with my PCB design questions.

I’ve also purchased the Olimex ARM-USB-TINY module to use for programming/debuging, and planned to use Yagarto along with OpenOCD. However, I am running into issues with the JTAG. At first, it was an OpenOCD configuration issue, but I resolved that one (failed to find the TINY).

Now, it indicates there is a problem with the JTAG chain. I’ve probed around quite a bit trying to determine issues. I copied the JTAG header design from the Olimex LPC-2148 schematic, and I have the same pullups/pulldowns. I probed the JTAG header and I appear to have the proper voltages. I do not have the jumper on RTCK as I always want JTAG enabled (the pulldown is there). I do have 3V3 on pins 1 and 2.

Here’s what I tried:

  1. I verified the VCC and GND pins on the JTAG header.

  2. I probed the VCC connections on the LPC2148 to verify it has power.

  3. I grounded NRST (/RESET on the LPC2148) to force reset and to recognize the 0 on P1.31 in case it wasn’t recognized.

Unfortunately I don’t have a digital o-scope, so I can’t capture JTAG traces. When I use my analog scope, I do see some activity on the JTAG lines, but I can’t capture it.

Is there a tool/utility to debug the JTAG connection using the FT2xx based wigglers? Is there anything else I can check?

Attached is a link with a PDF of the schematic, and the Eagle schematic and board files.

You can find them here: http://cid-3e6aa75359e23754.skydrive.li … px/USB2IEC

Thanks,

Pete