Register Descriptions; Bus Control Register 1 (Bcr1) - Hitachi SH7751 Hardware Manual

13.2

Register Descriptions

13.2.1

Bus Control Register 1 (BCR1)

Bus control register 1 (BCR1) is a 32-bit readable/writable register that specifies the function, bus
cycle status, etc., of each area.
BCR1 is initialized to H'00000000 by a power-on reset, but is not initialized by a manual reset or
in standby mode. External memory space other than area 0 should not be accessed until register
initialization is completed.
Bit: 31
ENDIAN
0/1*
Initial value:
R/W: R
Bit: 23
—
Initial value: 0
R/W: R
Bit: 15
HIZMEM
Initial value: 0
R/W: R/W
Bit: 7
A6BST2
Initial value: 0
R/W: R/W
Note: * These bits sample external pin values in a power-on reset by means of the
Rev. 3.0, 04/02, page 318 of 1064
30 29
MASTER A0MPX
0/1* 0/1*
R R
22 21
— A1MBC
0 0
R R/W
14 13
HIZCNT A0BST2
0 0
R/W R/W
6 5
A6BST1 A6BST0 DRAMTP2 DRAMTP1 DRAMTP0
0 0
R/W R/W
28 27
— —
0 0
R R
20 19
A4MBC
BREQEN
0 0
R/W R/W
12 11
A0BST1 A0BST0
0 0
R/W R/W
4 3
0 0
R/W R/W
26 25
DPUP IPUP
0 0
R/W R/W
18 17
—
MEMMPX DMABST
0 0
R R/W
10 9
A5BST2 A5BST1 A5BST0
0 0
R/W R/W
2 1
— A56PCM
0 0
R/W R

24
OPUP
0
R/W
16
0
R/W
8
0
R/W
0
0
R/W
pin.