CCU 3000, CCU 3000-I
CCU 3001, CCU 3001-I
Sequence in the main loop:
Remark:
It is important to program the watchdog register with the
new value before this value is memorized in the shadow
variable, becausethisprocedurecouldbeinterruptedby
the interrupt, which will program the watchdog with the
complementary value.
LDA watchdog_value
CMP #WATCHDOG_TIME
BNE SKIP_WD
;
STA watchdog_address
EOR #$FF
STA watchdog_value
SKIP_WD
...
D0...D7
latch
=
=
D
RES_DOG_1
Q
CLR
SWATCH
R/W
Φ2
+
Q
Q
D
CLR
RESET active
latch
RES_DOG
=
EN
D0
POWER
down
R/W
SWATCH
8–bit
CLR
16–bit
Φ2
counter
Fig. 2–17: Watchdog
Φ2
Trigger
D0...D7
watchdog is
retriggered
SWATCH
R/W
RES_DOG_1
Fig. 2–18: Timing watchdog
20
MICRONAS INTERMETALL
MICRONAS [ MICRONAS ]
