RL78/G1H CHAPTER 27 FLASH MEMORY
R01UH0575EJ0120 Rev. 1.20 Page 822 of 920
Dec 22, 2016
27.5.3 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
during both serial programming and self-programming.
Writing to and erasing areas outside the window range are disabled during self-programming. During serial
programming, however, areas outside the range specified as a window can be written and erased.
Figure 27 - 9 Flash Shield Window Setting Example
(Start Block: 04H, End Block: 06H)
Caution 1. If the rewrite-prohibited area of the boot cluster 0 overlaps with the flash shield window range, prohibition to
rewrite the boot cluster 0 takes priority.
Caution 2. The flash shield window can only be used for the code flash memory (and is not supported for the data flash
memory).
Remark
See 27.6 Security Settings to prohibit writing/erasing during serial programming.
Table 27 - 9 Relationship Between Flash Shield Window Function Setting/Change Methods and Commands
Programming Conditions
Window Range Setting/
Change Methods
Execution Commands
Block Erase Write
Self-programming Specify the starting and ending
blocks by the flash self-
programming library.
Block erasing is enabled only
within the window range.
Writing is enabled only within
the range of window range.
Serial 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.
Flash memory
area
√: Serial programming
×: Self-programming
Methods by which writing can be performed
Flash shield
range
Window range
Flash shield
range
00FFFH
00000H
01000H
01BFFH
01C00H
0FFFFH
Block 3FH
Block 3EH
Block 06H
(end block)
Block 05H
Block 04H
(start block)
Block 03H
Block 02H
Block 01H
Block 00H
√: Serial programming
√: Self-programming
√: Serial programming
×: Self-programming
To Next Page
Loading...
Need help?
General
