O Canada! > Canadian > TekSavvy > Upgrading Firmware on Thompson DCM475

Re: Upgrading Firmware on Thompson DCM475

Best link I've found thus far for something resembling a datasheet for it:

»www.spansion.com/Support/Datashe···A_00.pdf

Edit, yeah that's the part all right.
3.0V 32mbit SPI NOR flash memory chip.

I don't have any SPI masters at hand that I'm familiar with, but I do have a spare Arduino board here which undoubtedly groks SPI.

Otherwise I've got some USB->GPIO dongles that I can program to do the transfer. That might be quicker for me, because I've not bothered to learn the ins/outs of Arduino yet.

That's more or less what I've got in mind. Once I get it working here, I have several friends with 02.08 modems that will likely need upgrades soon. And I'd be willing to take on any others that are needy and aware enough to find me.

Curiously, the modem has a 4-pin header and a 4-pin socket near the flash chip, but it appears to be a 3V serial port for the processor rather than SPI for the flash. I should hook it up and see what it does at some point.

Doing a bit of simple math, my USB->GPIO adapter will be much too slow for the 32mbit flash contents, so I think I'll have to program the Arduino board to do it for me. They have a handy SPI library and tools, just gotta learn to use them. Might take a few days before I'm ready.

Cheers

Sign me up!

reply to mlord

That two places for the same port thing must just be a manufacturing feature of some sort. The white header is on all RCA modems, but it is hard to connect and reconnect to in bulk. The black one near the edge would be much more convenient to use on the assembly line. I sure wish they had the black one on DCM425s, it would make my life easier! But ya, still strange..

I'm sure you already know about using Nokia DKU-5 cables to connect to 3.3V serial ports:
»www.ebay.com/sch/i.html?_nkw=dku···m=&_ipg=

USBJTAG NT has data rates of 3/6/12MHz, so I'm guessing your 8MHz Arduino should be in the ball park for sure. Not a project I'd choose to take on myself, but I guess I'm just stuck in my analog past
--
electronicsguru.ca/for_sale/Cablemodems

I've now broken down and ordered an Arduino Pro Micro 3.3V board for this project. It should be here on Wednesday, and ought to simplify things: faster comms, and no need for level shifting.

Still looking for a cheaper source for the clip-on connector ($12 shipping for a $12 part??).

Cheers

Update: things are moving along.

Got the 3.3V Arduino board today -- have to get it running soon.
Also have all of the code written and tested (with logic analyzer) for dumping / programming flash on the Arduino.

Haven't found a more affordable source for the (excellent) recommended test clips, but just noticed that the EZ-Hook clips from the analyzer work very well on the in-circuit flash chip. So I'll just use those, since I've got lots of them on hand.

So I'm pretty close to hook-up time. Once I get the new 'duino going, the first task is to rip the 02.08 firmware a few times via different sequences, and do binary compares to judge the reliability of the communications. Then try erasing and reprogramming just the 02.08 firmware, and do readback/verify again.

If that all works, I'll get hold of the 02.16 modem and snatch a copy of the latest firmware from it.

Cheers

If I load 425-1.bin into USBJTAG and then inspect image0 I see the
string as follows:
CD4M525-.2803.-1118032S-.Sib.n

Flip the bits and I get:
DCM425-52.08.31-110823-SS.bin.

So maybe it is all just pairwise swapped?!?!

That's called Endianness

»en.wikipedia.org/wiki/Endianness

x86 are little endian

While in this case is likely MIPS based which is usually big endian.
--
TSI Gabe - TekSavvy Solutions Inc.
Authorized TSI employee ( »TekSavvy FAQ »Official support in the forum )

reply to mlord

The test setup.. forgot to disconnect the Logic Analyzer