HMS87C5216 ETC1 [List of Unclassifed Manufacturers], HMS87C5216 Datasheet - Page 59

• Manufacturer Part Number: HMS87C5216
• Description: CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER FOR UR(Universal Remocon) & WIRELESS KEYBOARD
• Manufacturer: ETC1 [List of Unclassifed Manufacturers]

14.2 WDT Interrupt Interval
WDT Interrupt (IFWDT) interval is determined by the interrupt
IFBIT interval of Basic Interval Timer and the value of WDT
Register.
-Interval of IFWDT = (IFBIT interval) * (WDTR value)
-Interval of IFWDT : 512 us * 1 = 512 us (MIN>)
-65,536us * 63 = 4,128,768 us (MAX>)
As IFBIT (Basic Interval Timer Interrupt Request) is used for in-
put clock of WDT, Input clock cycle is possible from 512 us to
65,536 us by BTS. (at fex = 4MHz)
N o t e : W h e n W D T R R e g i s t e r v a l u e i s 6 3 ( 3 F h )
(Caution) : Do not use ``0`` for WDTR Register value.
SEP. 2004 Ver 1.01
WDTR
CKCTLR
7
-
WDTCL
WDTCL
BTS2
7
0
0
0
0
1
1
1
1
-
0
1
WDTR5
BTS1
Watch DOG Timer Register
0
0
1
1
0
0
1
1
-
Automatically cleared, after one machine cycle
WDTON
WDTR4
Determine Interval of IFWDT
Interval of IFWDT = Value of WDTR × Interval of IFBIT
BTS0
0
1
0
1
0
1
0
1
Clock Control Register
Watch Dog Timer Operation
ENPCK
WDTR3
WDT Input clock
16,384 us
32,768 us
65,536 us
free-run
1,024 us
2,048 us
4,096 us
8,192 us
512 us
WDTR2
BTCL
*At Hardware reset time ,WDT starts automatically. Therefore,
the user must select the CKCTLR, WDTR before WDT over-
flow.
-Reset WDTR value = 0F h,15
-interval of WDT = 65,536 * 15 = 983040 us
Device come into the reset state by WDT
WDTR1
BTS2
(about 1second )
Max. Interval of WDT
1,032,192 us
2,064,384 us
4,128,768 us
129,024 us
258,048 us
516,096 us
WDTR0
BTS1
32,756 us
64,512 us
Output (*note1)
0
BTS0
W <00C8 h>
0
W <00C7 h>
HMS87C5216