RL78/G1P
CHAPTER 23 FLASH MEMORY
R01UH0895EJ0100 Rev.1.00
689
Nov 29, 2019
23.7.1 Flash shield window function
The flash shield window function is provided as one of the security functions for self-programming. It disables writing to
and erasing areas outside the range specified as a window only during self-programming.
The window range can be set by specifying the start and end blocks. The window range can be set or changed only
during on-board/off-board programming.
Writing to and erasing areas outside the window range are disabled during self-programming. During on-board/off-
board programming, however, areas outside the range specified as a window can be written and erased.
Figure 23-11. Flash Shield Window Setting Example
(Target Devices: RL78/G1P, Start Block: 04H, End Block: 06H)
Block 00H
Block 01H
Block 02H
Block 03H
Block 05H
Block 06H
(end block)
Block 04H
(start block)
Block 0FH
Block 0EH
: On-board/off-board programming
: Self-programming
: On-board/off-board programming
: Self-programming
: On-board/off-board programming
: Self-programming
Flash memory
area
Flash shield
range
Methods by which writing can be performed
Window range
Flash shield
range
03FFFH
01C00H
01BFFH
01000H
00FFFH
00000H
Caution The flash shield window can only be used for the code flash memory (and is not supported for the
data flash memory).
Table 23-14. Relationship Between Flash Shield Window Function Setting/Change Methods and Commands
Programming Conditions
Window Range Setting/Change
Methods
Execution Commands
Block Erase
Write
On-board/Off-board programming
Specify the starting and ending
blocks on GUI of dedicated flash
memory programmer, etc.
Block erasing is enabled also
outside the window range.
Writing is enabled also
outside the window range.
Remark
See
23.6 Security Settings
to prohibit writing/erasing during on-board/off-board programming.