ARM Cortex-M3

Bus Interface
ARM DDI 0337G Copyright © 2005-2008 ARM Limited. All rights reserved. 12-13
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12.10 Bit-band accesses
The System bus interface contains logic that controls bit-band accesses as follows:
• It remaps bit-band alias addresses to the bit-band region.
• For reads, it extracts the requested bit from the read byte, and returns this in the
Least Significant Bit (LSB) of the read data returned to the core.
• For writes, it converts the write to an atomic read-modify-write operation.
For more information about bit-banding, see Bit-banding on page 4-5.
Note
• The Cortex-M3 core does not stall during bit-band operations unless it attempts
to access the System bus while the bit-band operation is being carried out.