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19

32kHz ultra low power oscillator: Used for RTCs (Real-time-clock). These can run in the background and enable time-keeping, even when the controller core is sleeping. This enables to have a running clock without the high power consumption of the controller core. The 32kHz oscillators are pretty precise and typically have an error of less than a minute per ...


10

What these are for: 32kHz low power: "digital watch" crystal. Use this when you want to power down the main oscillator but not lose track of what time it is so you can wake up periodically. 32kHz RC: cheaper (no crystal), but less accurate. When you want a digital watch that doesn't tell the correct time. external fast crystal: for things like ...


8

After one day really hard challenging with the problem!! i finally figured out some important points that is i think worthy for other people out there so i decided to represent them: The STM32's DMA is a very quaint tool that i today realize that it can handle almost every kind of data transmission from a memory area to another memory area(such as moving ...


8

They are not strictly necessary but the vendor is attempting to cover as many use-cases with one part as they can. Some applications may want to use the internal oscillator, others may need a precise clock source, others may want low power consumption. Generally you will use only one in a specific design although in some cases the clock mode is changed ...


6

Here is the clock configuration in block-diagram form from ST's configuration tool (STM32F103). As you can see, there are internal oscillators and two oscillators that use external frequency-determining components (crystals or resonators typically). I have this configured to use an external 8MHz crystal and a 32.768 kHz watch crystal. I could have used the ...


5

You can select any stream you want (of course, DMA2 only). Channel selection is also irrelevant, because channels are related with requests. Notice the title of the Table 43, which is "DMA2 request mapping". Memory-to-memory transfers aren't triggered by DMA requests. Here is an example of Memory-to-memory transfer: #define MEMSIZE 32 uint16_t ...


3

The ATSAM family controllers typically have one really slow 32kHz oscillator used for low power applications, either with internal RC oscillator or external quartz crystal. And one high speed internal RC oscillator for "fast as it goes". In addition you can tweak around with PLL's, clock dividers and so on, and of course also provide external ...


2

Any stream can be used. No DMA request channel is used because the memory-to-memory transfer mode is selected and triggered in software.


1

The CMSIS-DSP matrix functions take integers or floats as data input, however your arrays are uint_16 so you may have data loss or wrong results due to the implicit conversions. if you used arm_mat_mult_fast_q15. what I would do is cast my input arrays to int32_t (Q31) and then do the multiplication. (No need to convert to matrices) //nRows1,nColumns1, ...


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