Bus Control Register H (Bcrh) - Renesas H8S Series Hardware Manual

6.2.4

Bus Control Register H (BCRH)

Bit : 7
ICIS1
Initial value : 1
R/W : R/W
BCRH is an 8-bit readable/writable register that selects enabling or disabling of idle cycle insertion, and the memory
interface for areas 2 to 5 and area 0.
BCRH is initialized to H'D0 by a power-on reset and in hardware standby mode. It is not initialized by a manual reset* or
in software standby mode.
Note: * Manual reset is only supported in the H8S/2357 ZTAT.
Bit 7—Idle Cycle Insert 1 (ICIS1): Selects whether or not one idle cycle state is to be inserted between bus cycles when
successive external read cycles are performed in different areas.
Bit 7
ICIS1
0
1
Bit 6—Idle Cycle Insert 0 (ICIS0): Selects whether or not one idle cycle state 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 area 0 is used as a burst ROM interface.
Bit 5
BRSTRM
0
1
Bit 4—Burst Cycle Select 1 (BRSTS1): Selects the number of burst cycles for the burst ROM interface.
Bit 4
BRSTS1
0
1
6 5
ICIS0 BRSTRM BRSTS1 BRSTS0
1 0
R/W R/W
Description
Idle cycle not inserted in case of successive external read cycles in different areas
Idle cycle inserted in case of successive external read cycles in different areas
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
Area 0 is basic bus interface
Area 0 is burst ROM interface
Description
Burst cycle comprises 1 state
Burst cycle comprises 2 states
4 3 2
RMTS2
1 0 0
R/W R/W R/W
1 0
RMTS1 RMTS0
0 0
R/W R/W
(Initial value)
(Initial value)
(Initial value)
(Initial value)
Rev.6.00 Oct.28.2004 page 113 of 1016
REJ09B0138-0600H