101-0303 Rabbit Semiconductor, 101-0303 Datasheet - Page 27

• Manufacturer Part Number: 101-0303
• Description: SMARTSCREEN OP7100 DISPLAY
• Manufacturer: Rabbit Semiconductor

Specifications of 101-0303

• Module/board Type: Single Board Computer Module with display
• For Use With/related Products: Single Board Computers
• Lead Free Status / RoHS Status: Vendor undefined / Vendor undefined

Of course, if the
will just power down.
Call the Dynamic C function
routine to make sure that the watchdog timer does not time out and thereby
reset the processor. The controller can continue to run at low voltages, and
so it might not be able to detect the low-voltage condition after the
watchdog timer resets the processor.
Watchdog Timer
To increase reliability, the ADM691’s watchdog timer forces a system reset if
a program does not notify the supervisor nominally at least every second. The
assumption is that if the program fails to “hit” the watchdog, the program
must be stuck in a loop or halted. The Dynamic C function for hitting the
OP7100
main(){
}
...
char dummy[24];
...
#define INT1 _ BIT
#INT _ VEC INT1 _ VEC power_fail_isr
#asm
#endasm
do whatever service, within allowable execution time
...
power_fail_isr::
loop:
timeout:
ld
call hitwd
ld
in
bit
jr
jp
DC
sp,dummy+24
bc,INT1
a,(c)
INT1_BIT, a ; check for status of /PFO
nz,loop
timeout
input voltage continues to decrease, then the OP7100
hitwd
0
; make sure no watchdog reset
; while low voltage
; load the read INT1 register
; to bc
; read the read INT1 register
; for /PFO
; wait until the brownout
; clears
; then...a tight loop to
; force a watchdog timeout,
; resetting the Z180
during the power-failure service
; bit 0
; force stack pointer
; to top of dummy vector
; to prevent overwriting
; code or data
Hardware 27