Figure 22.2 Software Standby Mode Application Example - Renesas H8S/2437 Hardware Manual

Software Standby Mode Application Example:
Figure 22.2 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 INTCR 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

Figure 22.2 Software Standby Mode Application Example

NMI exception Software standby mode
handling (power-down mode)
NMIEG=1
SSBY=1
SLEEP instruction
NMI exception
Oscillation
handling
stabilization
time t
OSC2
Rev. 1.00, 09/03, page 629 of 704