H8S-2350 RENESAS [Renesas Technology Corp], H8S-2350 Datasheet - Page 732

• Manufacturer Part Number: H8S-2350
• Description: 16-Bit Single-Chip Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 20 Power-Down Modes
20.6.5
I/O Port Status
In software standby mode, I/O port states are retained. If the OPE bit is set to 1, the address bus
and bus control signal output is also retained. Therefore, there is no reduction in current
dissipation for the output current when a high-level signal is output.
Current Dissipation during Oscillation Stabilization Wait Period
Current dissipation increases during the oscillation stabilization wait period.
Write Data Buffer Function
The write data buffer function and software standby mode cannot be used at the same time. When
the write data buffer function is used, the WDBE bit in BCRL should be cleared to 0 to cancel the
write data buffer function before entering software standby mode. Also check that external writes
have finished, by reading external addresses, etc., before executing a SLEEP instruction to enter
software standby mode. See section 6.9, Write Data Buffer Function, for details of the write data
buffer function.
20.7
20.7.1
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 oscillator stabilizes (at least 8 ms—the
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REJ09B0330-0300
Usage Notes
Hardware Standby Mode
Hardware Standby Mode
2
to MD
0
) while the H8S/2350 Group is in hardware