3.17 How the compiler handles bit-band objects placed outside bit-band regions

Bit-band objects must not be placed outside bit-band regions.

If you do inadvertently place a bit-band object outside a bit-band region, either using the at attribute, or using an integer pointer to a particular address, the compiler responds as follows:
  • If the bitband attribute is applied to an object type and --bitband is not specified on the command line, the compiler generates an error.
  • If the bitband attribute is applied to an object type and --bitband is specified on the command line, the compiler generates a warning, and ignores the request to bit-band.
  • If the bitband attribute is not applied to an object type and --bitband is specified on the command line, the compiler ignores the request to bit-band.
Related concepts
3.14 Compiler and processor support for bit-banding
3.15 Compiler type attribute, __attribute__((bitband))
3.16 --bitband compiler command-line option
Related reference
9.54 __attribute__((bitband)) type attribute
9.60 __attribute__((at(address))) variable attribute
7.13 --bitband
Non-ConfidentialPDF file icon PDF versionARM DUI0375F
Copyright © 2007, 2008, 2011, 2012, 2014 ARM. All rights reserved.