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eewiz · 2022-08-26

I see numerous examples of 4-wire SWD without a reset pin connection.I come from the PIC world where there is always Data, Clock and Reset for a Pgm/Dbg interface.I bought a Chinese STLink-V2 programmer/debugger and it has a reset pin as well as data...

eewiz · 2022-10-20

Not just memory. Cosmic ray or ESD may cause any transistor anywhere in the device to flip state.Sometimes even causing permanent destruction.

eewiz · 2022-10-20

See https://community.st.com/s/question/0D53W00001sj4uWSAQ

eewiz · 2022-10-20

Your vcsel driver chip has no chip select pin and also does not pay any attention to the I2C defined 7- or 10-bit addressing scheme.Your chip has a dumb shift register that co-opts I2Cs Start and Stop mechanism apparently due to not having a pin avai...

eewiz · 2022-10-07

Hello BHell.1All correct except for the 40K pull down. The micro's pull down has a MOSFET in series to VSS which has to be OFF because the micro is not powered. Your external 10K * 40nA = 400uV. So long as you hold the micro's pin voltage to less tha...

eewiz · 2022-10-06

The PU and PD resistances are real resistances in series with MOSFET that get turned on to enable the PU or PD current. Since the chip is not powered, the MOSFETs cannot be on so the pin will be floating.Until you try to pull the pin more than a diod...

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Which is Correct; 4-wire SWD without Reset OR 5-Wire SWD with Reset?

Re: Probability of bit flips

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Re: How to apply bitbang on i2c lines to 11 bit shift register in code ?

Re: STM32H750XBH6 What is the resistiance of a GPIO pin when the device is shut down = 0V to STM32 ? The pin is config. to be an output pin( push-pull) when the device has power.

Re: STM32H750XBH6 What is the resistiance of a GPIO pin when the device is shut down = 0V to STM32 ? The pin is config. to be an output pin( push-pull) when the device has power.