p2125vps20 Renesas Electronics Corporation., p2125vps20 Datasheet - Page 146

• Manufacturer Part Number: p2125vps20
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller (BSC)
6.3.2
WSCR is used to specify the data bus width for external address space access, the number of
access states, the wait mode, and the number of wait states for access to external address spaces.
The bus width and the number of access states for internal memory and internal I/O registers are
fixed regardless of the WSCR settings.
Rev. 1.00 Sep. 21, 2006 Page 108 of 658
REJ09B0310-0100
Bit
3
2
1
0
Bit
7
6
5
4
Bit Name
BRSTS0

IOS1
IOS0
Bit Name
—
—
ABW
AST
Wait State Control Register (WSCR)
Initial
Value
0
0
1
1
Initial
Value
1
1
1
1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
Burst Cycle Select 0
Selects the number of words that can be accessed by
burst access via the burst ROM interface.
0: Max, 4 words
1: Max, 8 words
Reserved
The initial value should not be changed.
IOS Select 1, 0
Select the address range where the IOS signal is output.
For details, refer to table 6.3.
Description
Reserved
These bits should not be written by 1.
Bus Width Control
The initial value should not be changed.
Access State Control
Selects 2 or 3 access states for access to the external
address space. This bit also enables or disables wait-state
insertion.
0: 2-state access space. Wait state insertion disabled in
1: 3-state access space. Wait state insertion enabled in
external address space access
external address space access