SH7055S Datasheet, PDF (789/1002 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7000 Series

(3) Flash Erase Code Select Register (FECS)
FECS selects download of the on-chip erasing program.
Bit
:7
6
5
4
3
2
1
0
—
—
—
—
—
—
—
EPVB
Initial value : 0
0
0
0
0
0
0
0
R/W
:R
R
R
R
R
R
R
R/W
Bits 7 to 1—Reserved: These bits are always read as 0. The write value should always be 0.
Bit 0—Erase Pulse Verify Block (EPVB): Selects the erasing program.
Bit 0
EPVB
0
1
Description
On-chip erasing program is not selected
[Clear condition] When transfer is completed
On-chip erasing program is selected
(Initial value)
(4) Flash Key Code Register (FKEY)
FKEY is a register for software protection that enables download of the on-chip program and
programming/erasing of flash memory. Before setting the SCO bit to 1 in order to download
the on-chip program or executing the downloaded programming/erasing program, these
processings cannot be executed if the key code is not written.
Bit
:
7
6
5
4
3
2
1
0
K7
K6
K5
K4
K3
K2
K1
K0
Initial value :
0
0
0
0
0
0
0
0
R/W
: R/W
R/W R/W
R/W R/W R/W
R/W R/W
Bits 7 to 0—Key Code (K7 to K0): Only when H'A5 is written, writing to the SCO bit is valid.
When a value other than H'A5 is written to FKEY, 1 cannot be written to the SCO bit. Therefore
downloading to the on-chip RAM cannot be executed.
Only when H'5A is written, programming/erasing of flash memory can be executed. Even if the
on-chip programming/erasing program is executed, flash memory cannot be programmed or
erased when a value other than H'5A is written to FKEY.
Rev.2.0, 07/03, page 751 of 960