20-101-1255 Rabbit Semiconductor, 20-101-1255 Datasheet - Page 96

• Manufacturer Part Number: 20-101-1255
• Description: COMPUTER SINGLE-BOARD BL4S100
• Manufacturer: Rabbit Semiconductor

Specifications of 20-101-1255

• Module/board Type: Single Board Computer Module
• Product: Modules
• Processor Type: BL4S100
• Sram: 512 KB
• Timers: 8 bit, 10 bit
• Number Of I/os: 20
• Backup Battery: 3 V Lithium Coin Type
• Operating Voltage: 9 V to 36 V
• Power Consumption: 2 W
• Board Size: 96 mm x 146 mm x 16 mm
• Description/function: Computer Module
• For Use With/related Products: BL4S100
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 316-1168

4.4.6 SRAM Use
The BL4S100 has a battery-backed data SRAM and a program-execution SRAM.
Dynamic C provides the
into the battery-backed SRAM. The compiler generates code that maintains two copies of
each protected variable in the battery-backed SRAM. The compiler also generates a flag to
indicate which copy of the protected variable is valid at the current time. This flag is also
stored in the battery-backed SRAM. When a protected variable is updated, the “inactive”
copy is modified, and is made “active” only when the update is 100% complete. This
assures the integrity of the data in case a reset or a power failure occurs during the update
process. At power-on the application program uses the active copy of the variable pointed
to by its associated flag.
The sample code below shows how a protected variable is defined and how its value can
be restored.
The
tery-backed SRAM without affecting the performance of the application program. Data
integrity is not assured when a reset or power failure occurs during the update process.
Additional information on
User’s Manual.
BL4S100 User’s Manual
bbram
protected nf_device nandFlash;
int main() {
...
_sysIsSoftReset();
keyword may also be used instead if there is a need to store a variable in bat-
protected
bbram
and
// restore any protected variables
keyword to identify variables that are to be placed
protected
variables is available in the Dynamic C
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