HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 609

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

18.7
18.7.1
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 dissipation. 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 (MD
standby mode.
Hardware standby mode is cleared by means of the STBY pin and the RES pin. When the STBY
pin is driven high while the RES pin is low, the reset state is set and clock oscillation is started.
Ensure that the RES pin is held low until the clock oscillation stabilizes (at least t
oscillation stabilization time—when using a crystal oscillator). When the RES pin is subsequently
driven high, a transition is made to the program execution state via the reset exception handling
state.
18.7.2
Figure 18.3 shows an example of hardware standby mode timing.
When the STBY pin is driven low after the RES pin has been driven low, a transition is made to
hardware standby mode. Hardware standby mode is cleared by driving the STBY pin high, waiting
for the oscillation stabilization time, then changing the RES pin from low to high.
Hardware Standby Mode
Hardware Standby Mode Timing
Hardware Standby Mode
2
to MD
0
) while the H8S/2245 Group is in hardware
Rev.3.00 Mar. 26, 2007 Page 567 of 772
Section 18 Power-Down Modes
REJ09B0355-0300
OSC1
—the