User`s manual

42 rabbit.com The Rabbit BIOS
FLASH_SIZE
Sets the amount of flash available. The default value is the internally defined _FLASH_SIZE_ The units
are the number of 4 KB pages of flash. In special situations, such as splitting flash between two coresident
programs, this may be modified to a smaller value than the actual available flash.
RAM_SIZE
Sets the amount of RAM available. The default value is the internally defined _RAM_SIZE_. The units
are the number of 4 KB pages of RAM. In special situations, such as splitting RAM between two coresi-
dent programs, this may be modified to a smaller value than the actual available RAM.
USE_TIMERA_PRESCALE
Uncomment this macro in Lib/Rabbit4000/BIOSLIB/sysconfig.c to run the peripheral clock
at the same frequency as the CPU clock instead of the standard “CPU clock/2.” This allows higher baud
rates if Timer A is used as the baud rate generator. USE_TIMERA_PRESCALE affects the resolution of
the PWM, Input Capture and Quadrature Decoder systems.
WATCHCODESIZE
This macro defines the size in bytes of the region used for interrupt vectors, debug kernel special variables,
and watch expressions. This macro must only be set to 0x800 or 0x1000 if the debug kernel is enabled, and
can be set to 0x400 otherwise.
To override the default, change its value in Lib/Rabbit4000/BIOSLIB/StdBios.c.
6.4.2 Advanced Options
The following macros are defined in STDBIOS.c. See the top of the BIOS source code and/or the various
configuration libraries for more options.
ENABLE_SPREADER
Default value is 1, which enables the clock spectrum spreader in normal mode to reduce EMI.
To override the default, define ENABLE_SPREADER in the project by using the Defines tab of the Project
Options dialog. Define the macro to 0 to disable spectrum spreading and to 2 for strong spreading.
NUM_RAM_WAITST,NUM_RAM2_WAITST, NUM_FLASH_WAITST
These macros are defined in boardtypes.lib. They define the number of wait states to be used for
read access to RAM and flash. Write access requires one more wait state than read access. These macros
are used to determine the relevant bit values in the memory bank control registers.
The only valid values for these wait state macros are 4, 2, 1 and 0.