Write Protect Function - Omron V690 Series User Manual

3-6 Write Protect Function

You can enable Write Protect for user data (8 kbytes) per page (256 bytes). Write Protect allows to prevent data being destroyed by
authorized writing.
♦ ♦ ♦ ♦ Scope of Write Protect
The addresses of pages from P0 to P31 are described below.
Page
P0 0000-00FF (h)
P1 0100-01FF (h)
P2 0200-02FF (h)
P30 1E00-1EFF (h)
P31 1F00-1FFF (h)
* (h) means that the value is a hexadecimal number.
♦ ♦ ♦ ♦ How to enable Write Protect
32 Bits of Write Protect data (4 bytes) of system data (refer to Section 2-2-3) correspond to each page. By rewriting a bit corresponding
to a write-protected page from 0 (disable) into 1 (enable), Write Protect to the page is enabled. To disable Write Protect, rewrite the bit
from 1 into 0.
Relation between bit of write-protected data and page is described below.
Code
7
A1 P7
A2 P15
A3 P23
A4 P31
P**: Status of Write Protect in page ** (between 0 and 31).
3-6
256 Bytes/page
Write-Protected Data (4 Bytes)
6 5 4
P6 P5 P4
P14 P13 P12
P22 P21 P20
P30 P29 P28
256 Bytes x 32 pages =
8192 bytes
Bit
3 2
P3 P2
P11 P10
P19 P18
P27 P26
Description
1 0
P1 P0 Status of Write Pro-
tect
P9 P8
0: Disabled (Default
P17 P16
value)
1: Enabled
P25 P24