Datasheet

Section 24 Power-Down Modes
Rev. 6.00 Mar. 18, 2010 Page 794 of 982
REJ09B0054-0600
24.4.4 Software Standby Mode Application Example
Figure 24.3 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
SLEEP instruction
Software standby mode
(power-down mode)
Oscillation
settling
time t
OSC2
NMI exception
handling
Figure 24.3 Software Standby Mode Application Example