SH7065 Datasheet, PDF (126/941 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

Section 3 Operating Modes
3.2.2 Mode Control Register (MODECR)
The mode control register (MODECR) is a 16-bit readable/writable register that selects the on-
chip ROM access mode.
MODECR is initialized to H'001C by a power-on reset, but is not initialized in standby mode.
Bit: 15
14
13
12
11
10
9
8
—
—
—
—
—
—
—
—
Initial value:
0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 7
6
5
4
3
2
1
0
—
—
— ROMMD —
—
—
—
Initial value:
0
0
0
1
1
1
0
0
R/W: R
R
R
R/W
R
R
R
R
Bits 15 to 5—Reserved: These bits are always read as 0 and should only be written with 0.
Bit 4—ROM Access Mode (ROMMD): Selects the on-chip ROM access mode. Normally, high-
speed mode should be used. For details, see section 8.4, Number of Access Cycles (SH7065A),
On-Chip ROM.
Bit 4: ROMMD
0
1
Description
On-chip ROM is accessed in high-speed mode
On-chip ROM is accessed in low-speed mode
(Initial value)
Bits 3 and 2—Reserved: These bits are always read as 1 and should only be written with 1.
Bits 1 and 0—Reserved: These bits are always read as 0 and should only be written with 0.
Rev. 5.00 Sep 11, 2006 page 104 of 916
REJ09B0332-0500