ISP1130DL Philips Semiconductors, ISP1130DL Datasheet - Page 43

• Manufacturer Part Number: ISP1130DL
• Description: Universal Serial Bus compound hub with integrated keyboard controller
• Manufacturer: Philips Semiconductors

Table 70: WDTKEY register: bit allocation
Table 72: WDT register: bit allocation
;at program start
WDT
PCON
WDT_INT
;call to subroutine which reloads the WDT
;watchdog subroutine
WATCHDOG:
Philips Semiconductors
9397 750 06895
Objective specification
Bit
Symbol
Reset
Access
Bit
Symbol
Reset
Access
W
W
7
0
7
0
10.7.1 Watchdog timer software example
EQU
EQU
EQU
LCALL
ORL
MOV
RET
Table 71: WDTKEY register: bit description
Table 73: WDT register: bit description
[1]
The following example shows how the Watchdog timer operation might be handled in
a user program.
Bit
7 to 0
Bit
7 to 0
W
W
6
1
6
0
This register can only be written if bit WLE in the PCON register is set to logic 1.
0FFH
087H
156
WATCHDOG
PCON,#10H
WDT,#WDT_INT
Symbol
WDK[7:0]
Symbol
WDL[7:0]
W
W
5
0
5
0
Rev. 01 — 23 March 2000
Description
Watchdog Key: a value of 55H disables the Watchdog timer and
inhibits the setting of bit PD in the PCON register. Any other value
than 55H will (re)enable the Watchdog timer.
Description
Watchdog Load value. The Watchdog timer interval is given by
(256
W
W
4
1
4
0
;address of watchdog timer SFR
;address of power-control SFR
;WDT internal 100 * prescaler overflow
;set WLE bit in PCON
;load watchdog timer with interval
WDL) in units of 1.024 ms (12 MHz clock frequency).
WDK[7:0]
WDL[7:0]
USB compound hub with keyboard controller
W
W
3
0
3
0
W
W
2
1
2
0
© Philips Electronics N.V. 2000. All rights reserved.
W
W
1
0
1
0
ISP1130
W
W
0
1
0
0
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