User`s manual

User’s Manual 31
4.5 Memory
4.5.1 SRAM
The RCM2300 is designed to accept 128K of SRAM packaged in an SOIC case.
4.5.2 Flash EPROM
The RCM2300 is also designed to accept 128K to 512K of flash EPROM packaged in a
TSOP case.
NOTE: Rabbit Semiconductor 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.
A Flash Memory Bank Select jumper configuration option based on 0 Ω surface-mounted
resistors exists at JP2. This option, used in conjunction with some configuration macros,
allows Dynamic C to compile two different co-resident programs for the upper and lower
halves of the 256K flash in such a way that both programs start at logical address 0000.
This is useful for applications that require a resident download manager and a separate
downloaded program. See Technical Note 218, Implementing a Serial Download Man-
ager for a 256K Flash, for details.
NOTE: Only the Normal Mode, which corresponds to using the full code space, is sup-
ported at the present time.
4.5.3 Dynamic C BIOS Source Files
The Dynamic C BIOS source files handle different standard RAM and flash EPROM sizes
automatically.