Microcontrollers User manual

UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 21 of 792
NXP Semiconductors
UM10237
Chapter 2: LPC24XX Memory mapping
All peripheral register addresses are word aligned (to 32 bit boundaries) regardless of
their size. This eliminates the need for byte lane mapping hardware that would be required
to allow byte (8 bit) or half-word (16 bit) accesses to occur at smaller boundaries. An
implication of this is that word and half-word registers must be accessed all at once. For
example, it is not possible to read or write the upper byte of a word register separately.
(1) LPC247x only.
Fig 8. AHB peripheral map