HD6432621 Hitachi, HD6432621 Datasheet - Page 455

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

Internal
reset signal
WT/IT
TME
Note: * The WOVF bit is set to 1 and then cleared to 0 by an internal reset.
Legend
WT/IT
TME
Notes: *1 The internal reset signal is generated only if the RSTE bit is set to 1.
Internal reset signal *
WDTOVF signal
H'FF
H'00
: Timer Mode Select bit
: Timer Enable bit
: Timer mode select bit
: Timer enable bit
TCNT value
Figure 12-4 (b) WDT1 Operation in Watchdog Timer Mode
*2 130 states when the RSTE bit is cleared to 0.
WT/IT= 1
TME= 1
H'FF
H'00
Figure 12-4 (a) WDT0 Watchdog Timer Operation
TCNT count
WT/IT=1
TME=1
1
Write H'00'
to TCNT
H'00 written
to TCNT
Occurrence
of internal reset
WDTOVF and
internal reset are
generated
Overflow
WOVF= 1*
515/516 states
Overflow
132 states *
WOVF=1
518 states
2
WT/IT= 1
TME= 1
WT/IT=1
TME=1
H'00 written
to TCNT
Write H'00'
to TCNT
Time
Time
411