F68HC11FN Fourth on?

[gab]

I have been using the F68HC11FN processors on one of or product control boards (using fourth) with no problems. We download our fourth program via a serial communications port into external battery backed memory.
The following processor on older stock work fine: F68HC11FN V3.5
NEW MICROS (C)
5C91F
QQAE0008.
The following processors don't work:
F68HC11FN V3.5
NEW MICROS (C)
0J84G
QQAA0209.

The problem that I'm seeing with these micros is that the fourth code on the micro seems to be there, but after downloading the product fourth code to external memory any command sent via serial port is recognised with an OK response in the hyperterminal window, but no action is performed. Even bad syntax gets the OK response. I'm using the same fourth code on both processors.

Things I've done or noticed:
The download to external memory doesn't take as long as it should. The "bad" micros download in 3.5 minutes instead of 4.5 minutes.

I've swapped processors between the two boards and the problem moves with the processor.

The "bad" micros will work on the board that they're swapped onto because the memory is battery backed-up. As soon as I re-download the code the problem surfaces.

When I checked FAQ I found a similar posting "F68HC11FN V3.5 versions..." by harrkev that talked about turning fourth off. That's the first I've heard of being able to do this and I was wondering where I can find information on how to tell what the status of this was and how to control it using the serial port. Is that the problem here?
I have very little documentation and none that can explain this. Is there something else I should look at?

Thank you in advance for your help with this,
Greg

[nmitech]

I've swapped processors between the two boards and the problem moves with the processor.

Thing that relates to the HC11 internal eeprom. Code could be corrupted in the eeprom.


The "bad" micros will work on the board that they're swapped onto because the memory is battery backed-up.
Thing that relates to the external battery-backed memory. Code could be corrupted in the battery-backed ram.


As soon as I re-download the code the problem surfaces.
Beside the above two suspections, there is a chance that the problem could caused by the terminal program dues to characters missed synchronization, and Hyperterminal is a good terminal program, but it is a known problem program for Max-FORTH communication, especially when it comes to download a FORTH program. To make it shorts, here is what i am sugesting,
1. Download a new terminal program from NMI's web site,
http://www.newmicros.com/temp/maxterm.zip (Dos based Terminal program)
http://www.newmicros.com/temp/NMITerm.zip (Window Terminal Program)
2. Erase the internal eeprom
3. Erase the external Battery-backed Ram
4. Reload your program with one of the the new Terminal Program above

Please do not skip step 2 & 3 above, and keep us posted.

[gab]

How do I erase the internal eprom?

After it is erased, how do I reload it?

[nmitech]

First, remove all the external memories on board such as Battery-backed ram, eeprom, or eprom, etc... Power up and enter the following in bold text to examine if there any code is preloaded in the internal eeprom that may caused the program crash,

HEX
B600 200 DUMP

If the data displays from address B600 to B7FF are all FF's then there is no need to erase the internal eeprom and you can skip this step

If the data displays with any hex # other than FF's then enter the following to erase,

HEX
170 80 FF FILL
170 B600 80 EEMOVE
170 B680 80 EEMOVE
170 B700 80 EEMOVE
170 B780 80 EEMOVE


Now dump the content of the internal eeprom again to makesure it's blank (FF's)

HEX
B600 200 DUMP


2. Next, Erasing the Battery-backed ram.
Leave the board power on and carefully install the battery ram on its socket and makesure do not install the ram backward. Enter the following,

HEX
"address" "size" ERASE

where "address" is the Battery-backed ram starting address
"size" is the size of the battery-backed ram

3. Re-download your program with one of the terminal program or option below,

MAXTERM,
Press ALT+D and enter the file to be downloaded

or NMITerm,
Click on FILE, SEND FILE and open file to be downloaded for download.