Datasheet

Table Of Contents
Section 22 Power-Down Modes
Page 692 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
22.4.4 Software Standby Mode Application Example
Figure 22.3 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.
Oscillator
φ
NMI
NMIEG
SSBY
NMI exception
handling
NMIEG = 1
SSBY = 1
Oscillation
stabilization
time t
OSC2
Software standby mode
(power-down mode)
NMI exception
handling
SLEEP instruction
Figure 22.3 Software Standby Mode Application Example