Standby Mode Transition And Pin States - Renesas H8/38024 Hardware Manual

• When an external clock is used
STS2 = 1, STS1 = 0, and STS0 = 1 should be set. Other values possible use, but CPU
sometimes will start operation before wait time completion.
• When the on-chip oscillator is used
8,192 states (STS2 = STS1 = STS0 = 0) is recommended if the on-chip oscillator is used on the
H8/38124 Group.
5.3.4

Standby Mode Transition and Pin States

When a SLEEP instruction is executed in active (high-speed) mode or active (medium-speed)
mode while bit SSBY is set to 1 and bit LSON is cleared to 0 in SYSCR1, and bit TMA3 is
cleared to 0 in TMA, a transition is made to standby mode. At the same time, pins go to the high-
impedance state (except pins for which the pull-up MOS is designated as on). Port 5 of the
HD64F38024 retains the previous pin state. Figure 5.2 shows the timing in this case.
φ
Internal data bus
Pins
Active (high-speed) mode or active (medium-speed) mode
Rev. 6.00, 08/04, page 128 of 628
SLEEP instruction fetch
SLEEP instruction execution
Port output
Figure 5.2 Standby Mode Transition and Pin States
Fetch of next instruction
Internal processing
High-impedance
Standby mode