Transition To Standby Mode And Pin States - Hitachi H8/3637 Hardware Manual

5.3.4

Transition to Standby Mode and Pin States

The system goes from active (high-speed) mode or active (medium-speed) mode to standby
mode when a SLEEP instruction is executed while the SSBY bit in SYSCR1 is set to 1, the
LSON bit in SYSCR1 is cleared to 0, and bit TMA3 in TMA is cleared to 0. At the same time,
pins go to the high-impedance state (except pins with MOS pull-up turned on). The timing in
this case is shown in figure 5.2.
ø
Internal
SLEEP instruction fetch
data bus
Pins
Active (high-speed) mode or active (medium-speed) mode
Figure 5.2 Transition to Standby Mode and Pin States
96
Next instruction fetch
SLEEP instruction
execution
Port output
Internal
processing
High impedance
Standby mode