p89c668hbbd NXP Semiconductors, p89c668hbbd Datasheet - Page 60

• Manufacturer Part Number: p89c668hbbd
• Description: 80c51 8-bit Flash Microcontroller Family
• Manufacturer: NXP Semiconductors

Philips Semiconductors
2002 Oct 28
80C51 8-bit Flash microcontroller family
16KB/32KB/64KB ISP/IAP Flash with 512B/1KB/2KB/8KB RAM
INIT_WATCHDOG:
;
;********************************************************************
;
; Main program goes here, but CALL WATCHDOG periodically.
;
;********************************************************************
;
WATCHDOG:
MOV CCAPM4, #4CH
MOV CCAP4L, #0FFH
MOV CCAP4H, #0FFH
ORL CMOD, #40H
CLR EA
MOV CCAP4L, #00
MOV CCAP4H, CH
SETB EA
RET
; Module 4 in compare mode
; Write to low byte first
; Before PCA timer counts up to
; FFFF Hex, these compare values
; must be changed
; Set the WDTE bit to enable the
; Hold off interrupts
; Next compare value is within
; 255 counts of the current PCA
; timer value
; watchdog timer without changing
; the other bits in CMOD
Figure 52. PCA Watchdog Timer Initialization Code
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P89C668
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