2014-01-12 03:40 PM
Hi,
is it possible to trigger a DMA transfer (8 bit data from gpios) on a falling edge on a gpio pin? (without using interrupts!!!). I think it is standard on all other mcu's with dma support (like kinetis mcus or nxp/ti devices) but i can't find any solution on ST cortex M3/M4 devices...:(. Greetz2014-01-12 04:40 PM
The STM32 is pretty lame it that regard, you can perhaps play games with a timer input and DMA triggering.
For clocked input, look at the camera interface (DCMI)2014-01-13 01:44 AM
I know the DCMI functionality but it is only available on devices with 100pins++ and is very expensive. So I want to emulate the DCMI.
I found your post about the same problem: Your code can solve my problem, right?2014-01-13 08:07 AM
ok that works.
But it is limited to 6 MHz on the input channel of the timer??? (on a stm32f103 @ 72 MHz(2014-01-13 08:25 AM
Your idea of very expensive, and
appear to be different. I haven't evaluated the maximum frequency for an F1 design.2014-01-13 09:19 AM
I wonder whether DMA from FSMC to SRAM (memory-to-memory) could be used for this purpose, employing NWAIT as the handshake signal.
I know that FSMC is available on the 100+ pin devices only, too; it's just an academic question :) JW