Datasheet

MAX6316–MAX6322
5-Pin µP Supervisory Circuits with
Watchdog and Manual Reset
11
Maxim Integrated
Figure 10 shows an example of a flow diagram where
the I/O driving the watchdog input is set high at the
beginning of the program, set low at the end of every
subroutine or loop, then set high again when the pro-
gram returns to the beginning. If the program should
hang in any subroutine, the problem would be quickly
corrected, since the I/O is continually set low and the
watchdog timer is allowed to time out, causing a reset
or interrupt to be issued. As described in the
Watchdog
Input Current section, this scheme results in higher time
average WDI current than does leaving WDI low for the
majority of the timeout period and periodically pulsing it
low-high-low.
START
SET WDI
HIGH
PROGRAM
CODE
SUBROUTINE OR
PROGRAM LOOP
SET WDI LOW
RETURN
POSSIBLE
INFINITE LOOP PATH
Figure 10. Watchdog Flow Diagram
GND
WDIMR
15V
CC
RESET
MAX6316
MAX6320
SOT23
TOP VIEW
2
34
GND
WDIMR
15V
CC
RESET
MAX6317
SOT23
2
34
GND
WDIRESET
15V
CC
RESET
MAX6318
MAX6321
SOT23
2
34
GND
MRRESET
15V
CC
RESET
MAX6319
MAX6322
SOT23
2
34
__________________Pin Configurations
MAX6316
GND
MANUAL
RESET
I/O
WDIMR
GND
µP
V
CC
V
IN
V
CC
RESET RESET
Typical Operating Circuit