h8s-2138 Renesas Electronics Corporation., h8s-2138 Datasheet - Page 194

• Manufacturer Part Number: h8s-2138
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 6 Bus Controller
6.2
6.2.1
BCR is an 8-bit readable/writable register that specifies the external memory space access mode,
and the extent of the I/O area when the I/O strobe function has been selected for the AS pin.
BCR is initialized to H'D7 by a reset and in hardware standby mode. It is not initialized in
software standby mode.
Bit 7—Idle Cycle Insert 1 (ICIS1): Reserved. Do not write 0 to this bit.
Bit 6—Idle Cycle Insert 0 (ICIS0): Selects whether or not a one-state idle cycle is to be inserted
between bus cycles when successive external read and external write cycles are performed.
Bit 6
ICIS0
0
1
Bit 5—Burst ROM Enable (BRSTRM): Selects whether external space is designated as a burst
ROM interface space. The selection applies to the entire external space .
Bit 5
BRSTRM
0
1
Rev. 4.00 Jun 06, 2006 page 140 of 1004
REJ09B0301-0400
Bit
Initial value
Read/Write
Bus Control Register (BCR)
Register Descriptions
Description
Idle cycle not inserted in case of successive external read and external write cycles
Idle cycle inserted in case of successive external read and external write cycles
Description
Basic bus interface
Burst ROM interface
ICIS1
R/W
7
1
ICIS0
R/W
6
1
BRSTRM
R/W
5
0
BRSTS1
R/W
4
1
BRSTS0
R/W
3
0
R/W
—
2
1
IOS1
R/W
1
1
(Initial value)
(Initial value)
IOS0
R/W
0
1