HD6412332 RENESAS [Renesas Technology Corp], HD6412332 Datasheet - Page 164

• Manufacturer Part Number: HD6412332
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

6.2
6.2.1
Modes 5 to 7
Mode 4
ABWCR is an 8-bit readable/writable register that designates each area as either 8-bit access space
or 16-bit access space.
ABWCR sets the data bus width for the external memory space. The bus width for on-chip
memory and internal I/O registers is fixed regardless of the settings in ABWCR.
After a reset and in hardware standby mode, ABWCR is initialized to H'FF in modes 5 to 7 * , and
to H'00 in mode 4. It is not initialized in software standby mode.
Note: * Modes 6 and 7 cannot be used in the ROMless version.
Bits 7 to 0—Area 7 to 0 Bus Width Control (ABW7 to ABW0): These bits select whether the
corresponding area is to be designated as 8-bit access space or 16-bit access space.
Bit n
ABWn
0
1
(n = 7 to 0)
Rev.4.00 Sep. 07, 2007 Page 134 of 1210
REJ09B0245-0400
Bit
Initial value :
R/W
Initial value :
R/W
Register Descriptions
Bus Width Control Register (ABWCR)
:
:
:
Description
Area n is designated for 16-bit access
Area n is designated for 8-bit access
ABW7
R/W
R/W
7
1
0
ABW6
R/W
R/W
6
1
0
ABW5
R/W
R/W
5
1
0
ABW4
R/W
R/W
4
1
0
ABW3
R/W
R/W
1
0
3
ABW2
R/W
R/W
2
1
0
ABW1
R/W
R/W
1
1
0
ABW0
R/W
R/W
0
1
0