Software Standby Mode Application Example; Figure 19.2 Software Standby Mode Application Example - Renesas H8SX/1500 Series Hardware Manual

Section 19 Power-Down Modes
19.7.4

Software Standby Mode Application Example

Figure 19.2 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
Iφ
NMI
NMIEG
SSBY

Figure 19.2 Software Standby Mode Application Example

Rev. 3.00 Mar. 14, 2006 Page 684 of 804
REJ09B0104-0300
NMI exception Software standby mode
handling (power-down mode)
NMIEG = 1
SSBY = 1
SLEEP instruction
NMI exception
Oscillation
handling
settling time
t
OSC2