HD6432621 Hitachi, HD6432621 Datasheet - Page 744

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

21A.6.4 Software Standby Mode Application Example
Figure 21A-3 shows an example in which a transition is made to software standby mode at the
falling edge on the NMI pin, and software standby mode is cleared at the rising edge on the NMI
pin.
In this example, an NMI interrupt is accepted with the NMIEG bit in SYSCR cleared to 0 (falling
edge specification), then the NMIEG bit is set to 1 (rising edge specification), the SSBY bit is set
to 1, and a SLEEP instruction is executed, causing a transition to software standby mode.
Software standby mode is then cleared at the rising edge on the NMI pin.
700
Oscillator
ø
NMI
NMIEG
SSBY
Figure 21A-3 Software Standby Mode Application Example
NMI exception
handling
NMIEG=1
SSBY=1
SLEEP instruction
Software standby mode
(power-down mode)
stabilization
Oscillation
time t
OSC2
NMI exception
handling