h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 119

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

6.3.1
ACSCR designates each area in the external address space as either 8-bit access space or 16-bit
access space. ACSCR designates each area in the external address space as either 2-state access
space or 3-state access space.
ACSCR is initialized to H'FF at a reset or in hardware standby mode but not initialized in software
standby mode.
Bit
7
6
5
4
3
2
1
0
Bit Name
ABW3
ABW2
ABW1
ABW0
AST3
AST2
AST1
AST0
Access Control Register (ACSCR)
Initial
Value
1
1
1
1
1
1
1
1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Area 3 to 0 Bus Width Control
These bits select whether the corresponding area is to
be designated as 8-bit access space or 16-bit access
space.
0: Area n is designated as 16-bit access space
1: Area n is designated as 8-bit access space
Area 3 to 0 Access State Control
These bits select whether the corresponding area is to
be designated as 2-state access space or 3-state
access space. Wait state insertion is enabled or
disabled at the same time.
0: Area n is designated as 2-state access space
1: Area n is designated as 3-state access space
Wait state insertion in area n access is disabled
Wait state insertion in area n access is enabled
Rev. 2.00, 03/04, page 87 of 534
(n = 3 to 0)