h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 508

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

16.2.3
Transition to Hardware Standby Mode: When the STBY pin is driven low, a transition is made
to hardware standby mode from any mode.
In hardware standby mode, all functions enter the reset state and stop operation, resulting in a
significant reduction in power consumption. As long as the prescribed voltage is supplied, on-chip
RAM data is retained. I/O ports are set to the high-impedance state.
In order to retain on-chip RAM data, the RAME bit in SYSCR should be cleared to 0 before
driving the STBY pin low. Do not change the state of the mode pins (MD2, MD1) while this LSI
is in hardware standby mode.
Rev. 2.00, 03/04, page 476 of 534
Oscillator
φ
NMI
NMIEG
SSBY
Hardware Standby Mode
Figure 16.2 Software Standby Mode Application Example
NMI exception
handling
NMIEG=1
SSBY=1
SLEEP instruction
Software standby mode
(power-down mode)
stabilization
Oscillation
time t
OSC2
NMI exception
handling