Bit-banding explained: A key feature of ARM Cortex-M3/M4


Yahya Tawil over at Atadiat wrote in to let us know about a corner-stone feature in ARM Cortex-M3 processors called bit-banding:

Writing a portable code is one of the concerns for developers, and while dealing with bit-fields is not standard in all compilers, it is not very advisable to use.
When a feature is available in the hardware itself, you will not have any issues in porting the code from vendor to vendor while both are using the same ARM Cortex-M3 core.

ARM Cortex-M3 features a 1 MB area in SRAM memory called bit-band region. In this region each bit can be accessed individually. To access to bit-band region bits you need to do so via an aliased region, where each word in this region is an alias to one bit in the bit-band region.

More details at Atadiat homepage.

Via the contact form.

from Dangerous Prototypes