User`s manual

User’s Manual 35
4.6 Memory
4.6.1 SRAM
RCM3400 boards have 256K–512K of SRAM installed at U6.
4.6.2 Flash EPROM
RCM3400 boards also have 256K–512K of flash EPROM installed at U4.
NOTE: Digi recommends that any customer applications should not be constrained by
the sector size of the flash EPROM since it may be necessary to change the sector size
in the future.
Writing to arbitrary flash memory addresses at run time is also discouraged. Instead,
define a “user block” area to store persistent data. The functions writeUserBlock and
readUserBlock are provided for this. Refer to the Rabbit 3000 Microprocessor
Designer’s Handbook
for additional information.
A Flash Memory Bank Select jumper configuration option based on 0  surface-mounted
resistors exists at header JP2 on the RCM3400 modules. This option is reserved for future
use.
4.6.3 Dynamic C BIOS Source Files
The Dynamic C BIOS source files handle different standard RAM and flash EPROM sizes
automatically.