HMS77C1000A Datasheet, PDF (26/45 Pages) Hynix Semiconductor – 8-BIT SINGLE-CHIP MICROCONTROLLERS

HMS77C1000A/HMS77C1001A
W
W
W
W
W
W
W
W
ADDRESS ; N/A
RESET VALUE : 0011_1111
LOWOPT PFDEN T0CS T0SE PSA
PS2
PS1
PS0
W = Writable bit
bit7
6
5
4
3
2
1
bit0 _{-n = Value at POR reset}
LOWOPT: Power-fail detection level select bit.
1 = Lowered detection level (1.8V @ 5V)
0 = Normal detection level (2.7V @ 5V)
PFDEN:
Power-fail detection enable bit
1 = Enable power-fail detection
0 = Disable power-fail detection
T0CS:
Timer 0 clock source select bit
1 = Transition on EC0 pin
0 = Internal instruction cycle clock
T0SE:
Timer 0 source edge select bit
1 = Increment on high-to-low transition on
EC0
0 = Increment on low-to-high transition on
EC0
PSA:
Prescaler assignment bit
1 = Prescaler assigned to the WDT
0 = Prescaler assigned to the Timer 0
PS2-PS0: Prescaler rate select bits)
Bit Value
000
001
010
011
100
101
110
111
Timer 0 rate
1:2
1:4
1:8
1:16
1:32
1:64
1:128
1:256
WDT rate
1:1
1:2
1:4
1:8
1:16
1:32
1:64
1:128
FIGURE 9-10 OPTION REGISTER
Oct. 2001 Ver. 2.0
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