AnsweredAssumed Answered

my USBi "locks" during "Link Compile Download"

Question asked by dzingoni on Apr 10, 2015
Latest reply on Dec 14, 2015 by DaveThib

Hi everybody,

I have a problem with a new simple board with an ADAU1701. I'm trying to control it with an USBi (I have both version 1.2 and 1.3).

When I perform a "link compile download" it looks like the USB get frozen .... the SCL line remains low, the yellow led on the USBi

keeps blinking .... in this state the USBi is "locked", that is the only way to come out of this situation is to disconnect the USB cable.

It's the same with version 1.2 and 1.3.


Now I checked everything on the board and connection and it's OK. This is confirmed by the fact that more simple actions, like

trying to use the "register control" window of the 1701 work OK, I can read and write with no problems if I do this as first action instead of downloading a program. Even reading all the registers is possible and OK.

It looks like downloading a firmware actually brings the USBi into a strange state where it keeps the SCL low.

I performed several checks and I can confirm that it's the USBi that actually pulls the SCL low.

I even tried to change the I2C pullups ... from 10k to 2K almost nothing changes ... sometimes I can download the firmware for one or two attempts, then everything locks .....


Is there any "firmware" or driver upgrade for the USBi? I'm actually using the latest beta Sigmastudio 3.11 Build 1 .

Isn't it a bug that actually it can LOCK the SCL down without ever recovering?


Moreover, is the 1701 too sensible to I2C pull-up value? What is a safe value to use ?

In a different situation I once run into problems when I discovered that everything was working with an USBi attached (the firmware was loaded by a microcontroller, the USBi was used to monitor the situation) while disconnecting the USBi caused everything to stop ... I changed by trial and error the pullups and ended up using 10k.