ADC Lock Failed after scope

Embedded Security ChipWhisperer Hardware
1

Hi.

CW1173
Why does a very simple …

>>> import chipwhisperer as cw
>>> scope = cw.scope()
>>> scope
cwlite Device
sn         = ...
fw_version = 
    major = 0
    minor = 65
    debug = 0
...

… generate an ADC Lock Failed red flashing LED?
The command itself is successful, but the device seems to be “locked” afterwards.

(How) can I reset the device without dis-/re-connecting the USB cable?

2

Connecting to the scope object in Python doesn’t configure the clock; you can use scope.default_setup() to get our default settings (including the clock).

You should (almost!) never have to re-connect the USB cable for normal use.

1 Like
3

Thanks for the quick answer.

It wasn’t about configuring the scope. My intention was simply to print the values, just like mentioned on your ChipWhisperer index page.

But how would I recover from this ADC Lock Failed red LED without re-connecting the USB cable? It says USBErrorIO .

Besides that … are the LED codes documented somewhere (LED, color, steady/flashing)?
Didn’t find anything in the RTFM pages.

4

Typically, the cause for this is that you have the scope still connected in a notebook somewhere, and are trying to connect to the same scope in a different notebook. In the first notebook, either run scope.dis(), or re-start the notebook, to avoid this. (this is explained here)

LEDs are documented at the top of the RTFM page (visually).

Normally, the blue “USB enumerated” and green “FPGA heartbeat” LEDs blink in a steady pattern to indicate that “we’re alive”.

1 Like
5

scope.dis() did the job, and you were right - there were more scope connections open.

I saw that one, but I was looking for a table with detailed steady/flashing explanations. I thought I’d missed. Never mind … the picture does the job as well … :grinning: :+1: