Trap Error, Cannot Enter Monitor

[mezz64]

Hey Guys,
After loading some botched code I repeatedly receive a Trap Occurred
message via MTTY.

The error reads:
Trap occured
Vector=Access Error FMT =03 SR =2704 FS =0C
Faulted PC = 02000598

D0:00000000 00000003 0000007D 00000042 00000000 05C5AB8F CF206080 15001080
A0:00000000 020372D6 020322B4 FFC0031C FFC0035C FFC007D4 021FFFD8 021FFFC4

The monitor prompt appears only briefly and pressing "A" does nothing
unless I do it repeatedly in which case I receive the menu prompt with
only a junk response.

I saw mentioned on the forums that a monitor recovery app is possible in
existence. Can this fix my issue?

I've already setup a support ticket, but I'm in kind of a time crunch so I figured i'd ask on the forums to see if there is some other solution I'm not aware of.

Thanks,
John

[mezz64]

An update and a new problem.

I was able to get into the monitor using a different PC, however when I try to program the flash I receive this error:
Starting address = 02000000
S Record End detected
S Recs start at the wrong address
Flash not programmed.

Anyone have any ideas?

Thanks!

[thomastaranowski]

It looks like you have a bad program image. Not a big deal, just reload at the monitor with the fla command. It may take more than one try if your serial connection is unstable.

Tom
~ sent from G1

[Forrest]

Just in case anyone gets this problem in the future and searches to find this ticket...

When faulty code is trapping and flashing the device with new code from the MTTTY serial tool, you should always power cycle the device (remove power plug, wait 2 seconds, insert power plug) and enter the monitor immediately (before application runs and trap occurs). This ensures that no memory or source is overwritten by bad function calls that are used in the fla process.

Flashing devices this way fixes most of the flash rewrite errors we see on the support web page.

[oleg_osov]

Hi everyone!

I just want to add a notice to a previous post. It would be useful for those who have no serial port. If one has no serial port it almost impossible to unplug USB cable, plug it again, connect Mttty and catch the very first boot. I have NO serial port on my home laptop, so I managed to recover from traps with a simple workaround.
1. Connect Mttty to a debug USB port and see the endless reboot cycle
2. Press 'reset' button and HOLD it for 5 seconds
3. Release the 'reset' button and catch the very first boot, press 'A'
4. type "fla" and flash your favourite reference 100% working app
5. enjoy!

I did about couple of dozens recovers with this method on a laptop, which has no serial port. I have no windows on my laptop, I run windows in the VirtualBox machine. This method works with virtual machines too.

[tod]

I would guess that most of us don't have actual serial ports, but USB to serial port adapaters work very well.

[ScottM]

Just wanted to toss a big thank you to oleg_osov - his approach worked for me nicely.