AT90USB162 ISP Signature reads as 0x1eFF82 ! What?

Go To Last Post
6 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hi All,

 

I'm pulling my hair out on this one - and I'm no uC beginner! I've designed in the good old AT90USB162 for the DFU functionality to allow my client to update the firmware via email (which sounded great at the time)
 
The IC is soldered down perfectly (if I do say so myself) but the USB doesn't do anything at all. Digging in further, using my trusty AVR Dragon programmer connected via ISP, it connects to the device fine (verified with a logic analyser too, SI checked by scope) but atprogram chokes on the device signature reading back "0x1eFF82" rather than the expected "0x1e9482"  

I did find a random comment in a dutch language forum:
 
My AT90USB162's that I bought from Farnell identify with ID: 0x1eff82 instead of 0x1e9482 as stated in the manual .... 
What do you think? Still chinese fake?

Atmel support writes ... 
Recently, wrong device signature issue has been reported in AT90USB162. It reads device signature as 0x1EFF82 instead of the right device signature 0x1E9482.

 
 
Which caused me some concern. I can't see how its a readback/SI/PSU problem as it's all clean, clocked at only 100kHz, and everything looks nice (by eye) and it's a stable result.  Are there really fake/counterfeit or just plain faulty parts out there getting into the main distis? I got my supply from Farnell, but even their buyers can make mistakes, so I'm not confident of what I have in front of me. Any thoughts?
 
Thanks,
Dave.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

As Farnell is now an Avnet company I cannot imagine that they want to buy from any other than the real manufacturer.

 

From your quote it suggests to me that Atmel support has made the remark that there are chips in the field with this specific ID, if true, then I wonder what they have brought up as solution.

 

just to rule some things out as it might be solved...

What version of studio are you using? and I assume you are using it to detect and read the device ID, correct?

normally any programming speed below 125KHz on a virgin chip should be OK.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Ooo. AVNET bought them out? I wasn't aware of that (maybe my eyes are too closed to all this acquisitions shenanigans) 

Anyway, I couldn't verify who the commentor was, but this is the link:

 

https://www.circuitsonline.net/f...

 

It was a very recent remark, so I wonder if the problem is very new (yay for me)

 

I am using Atmel Studio 7.0, with atprogram.exe directly on the command-line. I was trying to read the device info:

 

atprogram.exe -t avrdragon -i ISP -d AT90USB162 -cl 100khz --verbose info

 

Which I though was a good first non-destructive thing to do, and something I've done many times with other devices, but never this one since I just used the DFU bootloader in the past.

I've got an Olimex AT90USB162 eval PCB arriving today which I'm going to use for correlation. I'll report back what I find. I urgently need a solution, as my client is waiting for his electronics package!

 

Thanks.

Dave.

 

 

 

 

 

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

OK, so as expected when I swapped the chip from a known good board (Olimex AVR-USB-162) onto my PCB, the Olimex board reproduced the exact symptoms (dead USB, incorrect ISP signature) and my PCB worked fine.

I observed that the 'good part' had lighter package markings (it looks laser marked, not inked) and the bad part had much deeper (darker) markings.

 

Good part

Source: Olimex AVR-USB-162 dev board

Markings: 1248 W3248 [Week 48 of 2012] [ Lot W3248 ]

USB: DFU functional

ISP: signature 0x1e9482

 

Bad part:

Source Farnell order code 1455073

Markings: 804 A9PTJA [Week 04 of 2008] [ Lot A9PTJA ]

USB: Nothing. Dead

ISP: signature 0x1eff82

 

 

Nothing in the datasheet errata is relevant after Wk9 2007.

 

My feeling is this is 'mixing' or bad production test quality and not counterfeiting. (Speaking as an ex-IC ATE test programmer and and ex-IC designer engineer!) I got an earlier chip from somewhere deep in the inventory and it was a bad one. Perhaps the whole lot is bad.

 

So, I decided to open the box of parts and see what else is there. I have two more parts with exactly the same date and lot codes (as you would expect) so when I have time I'll solder them down and read out the ISP codes and see what we find.

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Just in case you hadn't noticed, there is another thread concerning bad signature with that part:

https://www.avrfreaks.net/forum/writing-signature-bytes

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Sigh. I was hoping it was just me. Thanks for the pointer. I'll try get some parts and support out of microchip.

 

Dave.