101-1226 Rabbit Semiconductor, 101-1226 Datasheet - Page 38

• Manufacturer Part Number: 101-1226
• Description: RCM3900 DEV KIT UNIVERSAL
• Manufacturer: Rabbit Semiconductor
• Series: RabbitCore 3900r
• Type: MPU Moduler

Specifications of 101-1226

• Contents: RabbitCore Module, Dev. Board, AC Adapter, Cable and Dynamic C® CD-Rom
• For Use With/related Products: RCM3900
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 316-1137

4.4 Memory
4.4.1 SRAM
RCM3900 boards have 512K of program-execution fast SRAM at U66. The program-
execution SRAM is not battery-backed. There are 512K of battery-backed data SRAM
installed at U9.
4.4.2 Flash EPROM
RCM3900 boards also have 512K of flash EPROM at U8.
Writing to arbitrary flash memory addresses at run time is discouraged. Instead, use a por-
tion of the “user block” area to store persistent data. The
readUserBlock()
processor Designer’s Handbook
tional information.
A Flash Memory Bank Select jumper configuration option based on 0  surface-mounted
resistors exists at header JP12 on the RCM3900 RabbitCore modules. 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 a 256K flash in such a way that both
programs start at logical address 0000. This option is not relevant to the RCM3900 Rab-
bitCore modules, which use 512K flash memories.
4.4.3 NAND Flash (RCM3900 only)
The RCM3900 model has a NAND flash to store data and Web pages. The NAND flash is
particularly suitable for mass-storage applications, but is generally unsuitable for direct
program execution. The NAND flash differs from parallel NOR flash (the type of flash
memory used to store program code on Rabbit-based boards and RabbitCore modules
currently in production) in two respects. First, the NAND flash requires error-correcting
code (ECC) for reliability. Although NAND flash manufacturers do guarantee that block 0
will be error-free, most manufacturers guarantee that a new NAND flash chip will be
shipped with a relatively small percentage of errors, and will not develop more than some
maximum number or percentage of errors over its rated lifetime of up to 100,000 writes.
Second, the standard NAND flash addressing method multiplexes commands, data, and
addresses on the same I/O pins, while requiring that certain control lines must be held stable
for the duration of the NAND flash access. The software function calls provided by Rabbit
for the NAND flash take care of the data-integrity and reliability attributes.
Sample programs in the
NAND flash. These sample programs are described in Section 3.2.1, “Use of NAND Flash
(RCM3900 only).”
RabbitCore RCM3900 User’s Manual
NOTE: Rabbit 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.
function calls are provided for this. Refer to the
SAMPLES\RCM3900\NANDFlash
and the
Dynamic C Function Reference Manual
writeUserBlock()
folder illustrate the use of the
Rabbit 3000 Micro-
for addi-
and
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