HD6412340 HITACHI [Hitachi Semiconductor], HD6412340 Datasheet - Page 80

• Manufacturer Part Number: HD6412340
• Description: H8S/2345 F-ZTAT Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

2.8.2
When the RES input goes low all current processing stops and the CPU enters the reset state. The
CPU enters the power-on reset state when the NMI pin is high, or the manual reset state when the
NMI pin is low. All interrupts are masked in the reset state. Reset exception handling starts when
the RES signal changes from low to high.
The reset state can also be entered by a watchdog timer overflow. For details, refer to section 11,
Watchdog Timer.
60
Notes: 1.
RES = high
Exception-handling state
Reset State
2.
Bus-released state
From any state except hardware standby mode, a transition to the reset state occurs whenever RES
goes low. A transition can also be made to the reset state when the watchdog timer overflows.
From any state, a transition to hardware standby mode occurs when STBY goes low.
Reset state
End of bus
request
End of
exception
handling
*1
Figure 2.15 State Transitions
Bus
request
STBY = high, RES = low
External interrupt
Request for
exception
handling
Program execution
End of bus request
Bus request
state
Interrupt
request
SLEEP
instruction
with
SSBY = 1
Hardware standby mode
SLEEP
instruction
with
SSBY = 0
Software standby mode
Power-down state
Sleep mode
*2