Bit-Band and DMA

Posted on May 17, 2011 at 13:05

Hi all,

I am having difficulty working out where in the STM32 the bit-banding is implemented. I'm happy to believe that it is part of the Cortex-M3 architecture because ARM talk about it in their TRMs, but it's not clear to me if it's part of the M3 core itself, or the AHB, or some other bit of hardware.

The reason I'm interested is because I have a system where I need to read from a GPIO on a timer, and store the bits read into a byte, so that eight values are in one byte in consecutive bits.

I considered using bit-banding and an IRQ routine, but if the DMA engines could be made to do this for me, it'd save a bunch of overhead and probably allow me to sample the GPIO more quickly (which would be good).

So, can the DMA engines use the bit-banding regions, or else perform a similar function in and of themselves?

Regards,

Daniel.