NXP Semiconductors
UM10300
User Manual OM6290
UM10300_1
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 1.0— 8 August 2008
18 of 30
As the crystal used on the board is a 12MHz crystal, the setting in the IDE has to
correspond with that. In order to achieve this, select Project -> Options for Target
‘OM6290’. The window below pops up. Set the Xtal frequency to 12 MHz.
The ARM7 CPU is capable of executing two instruction sets; the ARM instruction set
which is 32 bits wide or the Thumb instruction set which is 16 bits wide. This is a
compressed form of the ARM instruction set. Although the Thumb instructions will result
in lower code performance compared to ARM instructions, they will achieve a much
higher code density. High performance (speed) is not needed here and thus Thumb-
Mode is used. This can be selected under ‘Code Generation’, see Fig 7 below. For this,
select the tab ‘Target’.
Fig 7. Setting of some options
One restriction of the evaluation version of
μ
Vision is that the RealView Linker restricts
the base address for code/constants to 0xXX000000, 0xXX800000 or 0x00080000 where
XX is 00, 01, … , FF. This allows memory start addresses like 0x00000000 and
0x12800000.
Therefore the R/O Base needs to be set to 0 as indicated in Fig 8 for the code to
compile. Select tab ‘Linker’. This is valid if the RealView compiler is selected as
described below in 5.1.3 “Selection of the toolset”.
The meaning of R/O and R/W is as follows: