HD64F2149 Datasheet, PDF (957/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

BCR—Bus Control Register
H'FFC6
Bit
Initial value
Read/Write
7
ICIS1
1
R/W
6
5
4
3
2
ICIS0 BRSTRM BRSTS1 BRSTS0 —
1
0
1
0
1
R/W R/W R/W R/W R/W
Bus Controller
1
IOS1
1
R/W
0
IOS0
1
R/W
IOS select
Address for which AS/IOS pin
IOS1 IOS0 _{output goes low when IOSE = 1}
0 0 Low in access to address
H'(FF)F000 to H'(FF)F03F
1 Low in access to address
H'(FF)F000 to H'(FF)F0FF
1 0 Low in access to address
H'(FF)F000 to H'(FF)F3FF
1 Low in access to address
H'(FF)F000 to H'(FF)F7FF
Burst cycle select 0
0 Max. 4 words in burst access
1 Max. 8 words in burst access
Burst cycle select 1
0 Burst cycle comprises 1 state
1 Burst cycle comprises 2 states
Reserved bit
Burst ROM enable
0 Basic bus interface
1 Burst ROM interface
Idle cycle insert 0
0 Idle cycle not inserted in case of successive
external read and external write cycles
1 Idle cycle inserted in case of successive
external read and external write cycles
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