Datasheet

Table Of Contents
Section 6 Bus Controller
Page 112 of 846 REJ09B0140-0900 Rev. 9.00
Sep 16, 2010
H8S/2215 Group
6.3.1 Bus Width Control Register (ABWCR)
ABWCR designates each area for either 8-bit access or 16-bit access.
ABWCR sets the data bus width for the external memory space. The bus width for on-chip
memory and internal I/O registers except for the on-chip USB is fixed regardless of the settings in
ABWCR.
Bit Bit Name Initial Value R/W Description
7
6
5
4
3
2
1
0
ABW7
ABW6
*
2
ABW5
ABW4
ABW3
ABW2
ABW1
ABW0
1/0
*
1
1/0
*
1
1/0
*
1
1/0
*
1
1/0
*
1
1/0
*
1
1/0
*
1
1/0
*
1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Area 7 to 0 Bus Width Controls
These bits select whether the corresponding area is to
be designated for 8-bit access or 16-bit access.
0: Area n is designated for 16-bit access
1: Area n is designated for 8-bit access
Note: n = 7 to 0
Notes: 1. In modes 5 to 7, initial value of each bit is 1. In mode 4, initial value of each bit is 0.
2. The on-chip USB is allocated to area 6. Therefore this bit should be set to 1.