2014-01-27 02:27 PM
Given an F4 (F405 and F429) or even F2 ..
Is it possible for a DMA to be both MemoryToMemory and have the rate of delivery be set by a timer? ie: I'm effecting a copy from an array in RAM, to a GPIO. (a byte at a time, say, otherwise I could use SPI tricks.) With MemoryToPeripheral I think you can do it, but is M2M full speed only? Or is it possible to refer to a GPIO as a peripheral somehow? Thank you my friends, jeff #stm32f4-dma2014-06-11 06:03 PM
I guess you might want to ponder MicroSD (SDHC/SDXC) cards, the interface is clockable in the 24-37 MHz region, and writing large blocks (32KB) via FatFs isn't particularly slow (I'd expect >10MBps)
For TIM8 the channels/streams are defined in the Reference Manual RM0 The specific pin designations for the channels can be found in thehttp://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00037pdf
for the specific part. The lack of a proper ACK/REQ DMA interface is one of the missed opportunities in the STM32 designs.