STM32F405 (64 pin) device configuration question

mluessi · ‎2014-01-12

Posted on January 13, 2014 at 00:03

Hi,

I'm new to the STM32 processors and I'm using the Microexplorer tool to figure out the pin and device assignment. Unfortunately it seems like it isn't possible to activate an additional timer, which I need to generate a clock which is fed back into the SPI2 and SPI3 clock inputs. The timer should also support DMA request generation.

The devices I utilize are:

USB: FS device

USART: USART1 & USART3 in async mode

I2C: I2C1

SPI1: Full dp master with NSS

SPI2 & SPI3: Tx slave only unidirectional

TIM5: 4 x PWM output (using output-compare)

TIM8, TIM12: PWM input (using capture-compare)

ADC: ADC1_IN10 and ADC1_IN11 are used

+ 3x GPIO output + 1x GPIO input

Why is not possible to use TIM1 in output-compare mode on PA8 (TIM1_CH1)? Microexplorer tells me that there is a conflict OTG_FS, SPI1 and SPI2. Where does this conflict come from? Is it not possible to only use a single output pin (CH1) of the timer?

I attached the Microexplorer configuration. It would be great if someone could explain why this device conflict occurs.

Martin

Tesla DeLorean · ‎2014-01-12

Posted on January 13, 2014 at 01:18

What version of Micro Xplorer, 3.2 gets only slightly agitated about PA8 if you want to use SOF with USB

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mluessi · ‎2014-01-13

Posted on January 13, 2014 at 19:16

Yes, I'm using version 3.2. I have USB configured as OTG_FS Device-Only and PA8 doesn't seem to be used (it's gray in Micro Explorer).

Tesla DeLorean · ‎2014-01-13

Posted on January 13, 2014 at 20:24

And I was able to click on PA8 and assign it to TIM1_CH1, so I'm not sure this is a problem.

I used to do pin assignment manual, before Micro Xplorer existed. The F2/F4 part permit pin level assignment (the F1 had a peripheral block), and you can always use different timer channels.

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mluessi · ‎2014-01-13

Posted on January 13, 2014 at 21:29

Thanks, that makes sense. I had done the assignment manually before I realized micro explorer exists. I can manually enable PA8 to be TIM1_CH1 in the right window, but in the ''Tree interface'' I can't enable TIM1. I assume this is because some of the TIM1 pins are already used, so it won't be possible to fully use TIM1 and micro explorer marks TIM1 as unusable. I think the safest way is to test the pin assignment on the discovery F4 to make sure it works before producing a prototype.