Multilateration Mainboard Populated

I finished populating the mainboard and mounted the receiver cards on it. Here’s what it looks like:

I’m having a bit of a problem programming it. It programmed just fine the first few times I tried but now it work take at all. The CPU is running because I can see its serial output and the toggling of pins but the JTAG continually fails with a “Could not stop ARM device!” error. The only lead I have to fixing the problem is that the demo board I’ve been prototyping on has a older revision of the ARM and my current version of RealView MDK doesn’t have the new revision in the device menu. However, I wonder why it would have taken the programming at all if that’s the case.

I’ve tried the FLASH erase procedure but it still won’t communicate. I’ve checked continuity from all the JTAG signal lines to the ARM and they’re OK. I’ve also checked the JTAG signaling with the logic analyzer and the ARM seems to be responding. I can see where in the process the signaling deviates from the demo board but because the protocol is so obtuse, I don’t know why it’s failing.

Update: 6:07 PM

Here is a capture of the JTAG signals and where the demo board and my board deviate:

JTAG Working on Demo Board

JTAG Working on Demo Board

JTAG Not Working on Mainboard

JTAG Not Working on Mainboard

The JTAG signals deviate from marker A forward.  After that point, the JTAG looks like it’s trying over and over again to get the response it’s expecting as those black areas on the bottom image are a repeating pattern of 18 bytes.

I requested a quote from Keil for a renewal of our software maintainace agreement and it’ll run about $1469.  I’ll look a little further tomorrow but it’s looking like it may that I’m trying to program it as an older revision of the processor.