BL4S100 User’s Manual
32
3.7 Memory
3.7.1 SRAM
All BL4S100 boards have 512KB of battery-backed data SRAM, and 512KB–1MB of fast
program execution SRAM.
3.7.2 Flash Memory
BL4S100 boards have 1MB—2MB of serial flash memory.
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.
3.7.3 VBAT RAM Memory
The tamper detection feature of the Rabbit microprocessor can be used to detect any
attempt to enter the bootstrap mode. When such an attempt is detected, the VBAT RAM
memory in the Rabbit microprocessor is erased. The serial bootloader on the BL4S100
boards uses the bootstrap mode to load the SRAM, which erases the VBAT RAM memory
on any reset, and so it cannot be used for tamper detection.
electronic components distributor
