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STM32F4xx minimal circuit CAN Bootloader + Questions on STM32F4Discovery & it's ST-Link2

Question asked by l..michael on Apr 17, 2013
Latest reply on Apr 17, 2013 by l..michael

currently I am trying to analyze the STM32F4Discovery schematic to get a minimal circuit using a STM32F407 oder STM32F405 in LQFP100. So I started an now ended up completely confused with a whole bunch of questions in my head:

1. Could anyone have a look at my minimal circuit?

>>>>>>>>>>>>>>>>>>>>>>>      Minimal Circuit  <<<<<<<<<<<<<<<<<<<<<<<<<<Unbenannt5.PNG

KLICK above image

Any suggestions for improvements ???

2. Could you again have a look at my JTAG connection? I need to use the STM32F4Discovery ST-Link2 with 6pin connector. Did I wire up my F405 correctly? Did I forget anything? What is it about that MCO pin (see picture of STM32F4Discovery ST-Link2 schematic). This one is connected on the STM32F4Discovery board but not via the SWD-connector. What is it? Do I need it? *confusion*. As far as I could get it the MCO is connected to PH0 (Oscillator in). What why and why not on SWD-connector?Unbenannt3.PNG

3. Reading through the STM32F4Discovery manual I found a note I don't get:

Why does it say I need to remove SB11 in order to use the CN2 (SWD-Connector) NRST pin? What happens if I don't remove SB11? I just don't get it.

4. Could you again have a look at my minimal schmematic pdf file. This time it's all about the bootloader. I intend to use the CAN-Bootloader (CAN2). Is that wiring correct? In AN2606 (general bootloader) it says: "The hardware required to put the STM32F40xxx/41xxx into System memory boot mode consists of any circuitry, switch or jumper, capable of holding the BOOT0 pin high and the BOOT1 pin low during reset.". Having a look at the STM32F4Discovery schematics I can see both BOOT0 and BOOT1 connected via a voltage divider between VDD(3V3) and GND with 10K and 510R.

But *** WHY WHY WHY? By the way SB18 and SB19 are fitted. Any explanations?

Thank you very much and sorry for my confusing schematic. I'm just getting into it. Thanks for your patience and for reading.

Greetings from Germany