Ambit 255 pinouts

[thesparky]

Does anybody have the pin outs to connect my usbjtag nt to an ambit 250

i flashed it successfully but stupidly wanted to update it to haxorware 11 rev39, i know now why it wouldnt update via the GUI, i use firefox and i should have used internet explorer, firefox just hangs on a firmware update

never mind

anyway, so i used a max232 and hyper terminal, loaded the flash on to it, but didnt realise it wasnt a full 2Kb flash but a 1Kb software update oops

the modem now doesnt give a P option so im guessing the best way forward is to jtag it and use Ujmodem to detect the flash and hopefully get it up and running again

thanks for reading this and any help would be great

[Koevoet]

No jtag points on the 250/255 , you will more than likely require a TSOP lift and reprogram that way with a suitable programmer.

Regards

[thesparky]

many thanks koevoet

i do have a willem with a tsop 48, is it just a matter of erasing the chip and loading on the 2Kb flash or is the image thats needed different?,

i recall something about the checksum but that could well have been related to cable boxes?

[thesparky]

i meant to ask if theres no jtag pinout for the 255 why is there a setting in USB JTAG NT 0.42 program for it?

[Koevoet]

It shouldn't really be there that config xml for the A250 as the dll was setup on the old usbjtag by usbbdm for a webstar running old ambit firmware , i asked usbbdm to name it 250 as the firmware was related to it , but it actually has nothing to do with the modem itself as we have no found any suitable (if any) jtag points on the modem.

all you need to do is load the 2M dump via your programmer , you may have to byte-swap the firmware to get a successful load.

Regards

[usbbdm]

I used one SB5100 and solder this one "48 Pin TSOP SMT Socket for Prototype Test Programming"
Like this
http://cgi.ebay.com/48-Pin-TSOP-SMT-Soc ... 803wt_1137

Then use SB5100 and USB JTAG NT to program anything I want. This is a much faster programmer than any programmer.

To use it open the socket and put the chip in. Do not close the socket.
1. Power on the modem.
2. enter TRAP ON (you need to send poke sequence).
3. Close the socket.
4. Load the binary (2M).
5. Program the chip and cmpram.
6. Power off the modem and remove the chip. Do not try to run the app since this app might not work at all.

You can build this programmer relative cheap if you already have JTAG NT and some modems sitting around.

[CAPONE]

i meant to ask if theres no jtag pinout for the 255 why is there a setting in USB JTAG NT 0.42 program for it?

I belive its for the SPI Chip. You can Solder JTAG NT Cables to the SPI Chip and read and Program them. Similar to the SB5101U.