2012-11-29 12:45 AM
I am trying to use DMA1 Stream 1 Channel 4 in the STM32F205ZE
(IAR Embedded Workbench IDE). Attempts to configure the DMA (using the Std Peripherals library) result in no change in the register values (all values remain zeroes). Attempts to write directly to the register memory also make no change. (Doing the same thing with, say, UART3, works fine). Any ideas why the memory around 0x40026000 might remain resistant to my attempts to configure it? Thanks 0x40004808 OK #dma-stm322012-11-29 12:59 AM
You might have forgotten to enable the clock for DMA1 in RCC (in RCC_AHB1ENR).
JW2012-11-29 03:02 AM
Thanks, but no - the line
RCC_AHB1PeriphResetCmd(RCC_AHB1Periph_DMA1, ENABLE); is in place.2012-11-29 04:35 AM
Thanks, but no - the line RCC_AHB1PeriphResetCmd(RCC_AHB1Periph_DMA1, ENABLE); is in place.
No you need to enable the CLOCK, not RESET the peripheral.2012-11-29 06:04 AM
This is a recurring problem here. The ''instructions'' in the ehm ''library'' are faulty.
JW2012-11-29 02:11 PM
Curses! Copying and pasting the ''RCC_AHB1PeriphClockCmd'' with so many peripherals being enabled. Somewhere along the line I ended up with ''RCC_AHB1PeriphResetCmd'' in the clipboard, and it looks similar to ''RCC_AHB1PeriphClockCmd'' when you have lots of lines of code!
Thanks. Better now.