STM32F091RCH using my design. Technical review is required

[Ssona.1]

Any boot flash is required for this IC,

Any standard JTAG pin out and connector part numbers are available.

Decoupling capacitor and crystal values are need to verify.

[Uwe Bonnes]

Where is your question? What should get reviewed?

[Ssona.1]

Sorry , i missed the attachment. Need to review this schematic. in the following aspect :

1.Any boot flash is required or not for this controller. If yes provide the details.

2.JTAG interface connector interface, Connector part number and matting flashing part number.

3.External crystal oscillator and its capacitor value details are required

4.What is the maximum power consumption of the IC.

5.Decoupling capacitor details 

[Jack Peacock_2]

External boot flash is not required.

Use any of the common JTAG pinouts recommended for ARM Cortex (the M0 series uses SWD but the pinouts are similar). A Google search will show this. Try the website for your JTAG adapter for a specific part number.

All STM32 parts have an internal RC oscillator, crystal is not required. ST has an app note on calculating capacitor and resistor load for external crystals, based on frequency.

Power consumption varies depending on operating mode and enabled peripherals. The datasheet lists the options.

One cap per power/ground pin pair, plus a 10uF bulk at a minimum. See the datasheet and evaluation boards for more examples.

[Ssona.1]

Thanks Jack Peacock_2.

Here with i attached power consumption and crystal capacitor values.

i found power consumption of controller is ~35mA is the maximum current. Is it right one.

Then based on application note for crystal oscillator capacitors are founded, i am getting 11pF for 8MHz oscillator.

App note used to find the capacitor values.

(https://www.st.com/resource/en/application_note/cd00221665-oscillator-design-guide-for-stm8afals-stm32-mcus-and-mpus-stmicroelectronics.pdf)

Can you share the JTAG - SWD pinout link and Flasher pinout as well, i need a price cheaper flasher.

Yes, i already followed the decoupling capacitor as per datasheets.

[berendi]

The JTAG/SWD interface needs ground and Vdd too.

Why are there 3 I2C interfaces, when the MCU has only 2? PB6/PB7 and PB8/PB9 are alternative pins for the same I2C controller, so unless there is an address collision between the slaves, there is no need to separate them. Switching to alternate pins in runtime can confuse the I2C controller as it will detect false start/stop events and must be reset every time. It won't even work at all unless the MCU is a master on both of them. Don't forget the I2C pullup resistors.

External oscillators are required only if the application needs better clock accuracy than the internal ones. See HSI oscillator characteristics in the datasheet. The low-frequency oscillator is used for long term timekeeping.

[Ssona.1]

Hi berendi,

The address collision will be taken care in the I2C bus. Pull Up resistor added for I2C resistor.

We will plan to use internal oscillator.

Can you please share the JTAG pinout and target board connector part number for V3SET.

regards,

selvakumar s

[Piranha]

Parts supplied from VDDA must be grounded to VSSA. That means C33, C34 must be connected to AGND.

Is R22 placeholder present only as a pads for manual shorting? If that's the case, consider replacing it with something more convenient.

For a LSE crystal ABS25 load capacitors the 4,3 pF doesn't seem like appropriate values. If the load capacitance is 12,5 pF and PCB traces are short, capacitors should be in a 18-22 pF range for 2 layer boards and 15-18 pF for 4+ layer boards. Similarly for a HSE crystal with 20 pF load capacitance most likely the capacitors should be in a 30-39 pF range. Put the wrong ones and the actual ppm offset will be out of specification by a multiple amount of the specified value. Take a look at AN2867 and this:

https://blog.adafruit.com/2012/01/24/choosing-the-right-crystal-and-caps-for-your-design/

[Ssona.1]

Hi Piranaha,

Thanks for your comments , I will update the C33 and C34. I will check the recommended application note for crystal.

We planned to use V3SET Programmer. So we need Target board 20pin JTAG connector part, Can you please suggest.

regards,

selvakumar s

[Ssona.1]

Hi all,

Is there any VCAP required for this IC ?

Please provide your comment.