HD6413007F20 Datasheet, PDF (93/798 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

3. MCU Operating Modes
Bit 1⎯Software Standby Output Port Enable (SSOE): Specifies whether the address bus and
bus control signals (CS₀ to CS₇, AS, RD, HWR, LWR, UCAS, LCAS, and RFSH) are kept as
outputs or fixed high, or placed in the high-impedance state in software standby mode.
Bit 1
SSOE
0
1
Description
In software standby mode, the address bus and bus control signals are all high-
impedance
(Initial value)
In software standby mode, the address bus retains its output state and bus control
signals are fixed high
Bit 0⎯RAM Enable (RAME): Enables or disables the on-chip RAM. The RAME bit is
initialized by the rising edge of the RES signal. It is not initialized in software standby mode.
Bit 0
RAME
0
1
Description
On-chip RAM is disabled
On-chip RAM is enabled
(Initial value)
3.4 Operating Mode Descriptions
3.4.1 Mode 1
A maximum 1-Mbyte address space can be accessed. The initial bus mode after a reset is 8 bits,
with 8-bit access to all areas. If at least one area is designated for 16-bit access in ABWCR, the
bus mode switches to 16 bits.
3.4.2 Mode 2
A maximum 1-Mbyte address space can be accessed. The initial bus mode after a reset is 16 bits,
with 16-bit access to all areas. If all areas are designated for 8-bit access in ABWCR, the bus
mode switches to 8 bits.
Rev.5.00 Sep. 12, 2007 Page 63 of 764
REJ09B0396-0500