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How to recognize which STM32F7xx microcontroller has DSI and which doesn't?

Question asked by Piwowarski.Pawel.001 on May 8, 2017
Latest reply on May 12, 2017 by Khouloud G

Hi.

So, main page says:

So it suggest that STM32F7x8 and 7x9 has DSI, and lowest (7x2 to 7x7) doesn't.

Unfortunately if we enter a specific type of microcontroller, exampleSTM32F777BI, we see general information about all family, not information about this specific microcontroller:

So we will not see if the DSI is or not.

 

Maybe compare table?

These two should not have a DSI.

 

But i have STM32F769BI microcontrollers and PCB for it (my own design, for microcontrollers without DSI). And after soldering something make me a short curcuit on the VCC line (uC takes a lot of current and get hot). I measured another uC pins with the multimeter (before soldering to PCB) and it looks like it corresponds to a pinut of DSI controller.

 

All table clearly states that it should not have DSI (uC with DSI on red, my uC (without DSI as I expect), on green):

The difference between uC with and without is DSI is mainly on 125pin (pin 125), because it is VDD12DSI or VSS depending on presence of DSI.

So the microcontroller VDD12DSI pin, gets on the VSS pad on my PCB. And make a short circuit.

 

125 pin in my STM32F769BI (outside the PCB) do not have connection to other VSS pins. So i guess that is not a VSS pin, and it is VDD12DSI pin.

And pins 122 and 128 are not floating. So i guess they are not PJ10 and PK2, but they ale both VSSDSI.

 

Finally, how to choose a microcontroller without DSI (to fit my PCBs), since you cannot rely on the table and the description?

Thanks.

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