80C575 Datasheet, PDF (18/40 Pages) NXP Semiconductors – 80C51 8-bit microcontroller family 8K/256 OTP/ROM/ROMless, 4 comparator, failure detect circuitry, watchdog timer

Philips Semiconductors
80C51 8-bit microcontroller family
8K/256 OTP/ROM/ROMless, 4 comparator, failure detect circuitry, watchdog timer
Product specification
80C575/83C575/
87C575
WRITE TO
CCAP4H
RESET
WRITE TO
CCAP4L
0
1
ENABLE
CIDL
WDTE
––
––
CCAP4H
CCAP4L
16–BIT COMPARATOR
MATCH
––
CPS1
CPS0
ECF
CMOD
(D9H)
RESET
CH
CL
PCA TIMER/COUNTER
––
ECOMn CAPPn CAPNn MATn
TOGn
PWMn
ECCFn
CCAPM4
(DEH)
0
0
1
X
0
X
Figure 13. PCA Watchdog Timer
SU00042
WATCHDOG FEED SEQUENCE
MOV WFEED1,#0A5H
MOV WFEED2,#5AH
OSC/12
PRESCALER
WDL
(C1H)
8–BIT DOWN
COUNTER
RESET
SHADOW REGISTER
FOR WDCON
PRE2
PRE1
PRE0
LVRE
OFRE
WDRUN
WDTOF
WDMOD
WDCON
(C0H)
Figure 14. Watchdog Timer in 87C575 and 80C575 / 83C575 (EA = 0)
SU00240
1998 May 01
18