OP7100
Hardware
s
27
main(){
...
}
...
char dummy[24];
...
#define NMI_BIT
0
; bit 0
#JUMP_VEC NMI_VEC myint
#asm
myint::
ld sp,dummy+24
; force stack pointer
; to top of dummy vector
; to prevent overwriting
; code or data
do whatever service, within allowable execution time
loop:
call hitwd
; make sure no watchdog reset
; while low voltage
ld bc,NMI
; load the read NMI register
; to bc
in a,(c)
; read the read NMI register
; for /PFO
bit NMI_BIT, a
; check for status of /PFO
jr z,loop
; wait until the brownout
; clears
timeout:
; then...a tight loop to
; force a watchdog timeout,
jp timeout
; resetting the Z180
#endasm
Of course, if the
DC
input voltage continues to decrease, then the OP7100
will just power down.
Call the Dynamic C function
hitwd
during the power-failure service
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 ADM691s 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
Содержание OP7100
Страница 1: ...OP7100 Serial Graphic Display User s Manual 019 0065 020418 J ...
Страница 10: ...OP7100 x s About This Manual ...
Страница 16: ...OP7100 16 s Overview ...
Страница 50: ...OP7100 50 s Hardware ...
Страница 51: ...OP7100 Software s 51 CHAPTER 4 SOFTWARE Chapter 4 describes the Dynamic C functions used with the OP7100 ...
Страница 72: ...OP7100 72 s Software ...
Страница 80: ...OP7100 80 s Graphics Programming ...
Страница 86: ...OP7100 86 s Installation ...
Страница 96: ...OP7100 96 s Specifications ...
Страница 110: ...110 s Serial Interface Board 2 OP7100 ...
Страница 111: ...OP7100 Backup Battery s 111 APPENDIX E BACKUP BATTERY ...
Страница 114: ...OP7100 114 s Backup Battery ...
Страница 122: ...OP7100 122 s Index ...