MCP98243 Microchip Technology Inc., MCP98243 Datasheet - Page 39

• Manufacturer Part Number: MCP98243
• Description: Memory Module Temperature Sensor W/ Eeprom For Spd
• Manufacturer: Microchip Technology Inc.

5.3.3.3
Once the PWP register is written, the lower half of the
memory will be permanent protected and the device
will not acknowledge any command. The protected
area of the memory can not be cleared, reversed, or re-
written. If a write is attempted to the protected area, the
device will acknowledge the address byte and word
address but not the data byte. (See
Table
FIGURE 5-18:
Communication”).
© 2009 Microchip Technology Inc.
SCL
SDA
5-6).
Note:
PWP (Permanent Write Protect)
S
Unlike SWP and CWP, V
See
1
0
2
1
Timing Diagram for Setting Permanent Write Protect (See Section 4.0 “Serial
Figure 2-13
Address Byte
3
1
4
0
5
A
2
A
6
1
and Section 5.3.3 “Write Protection”.
A
7
0
Table 5-5
MCP98243
W
8
HV
A
C
K
must be within the range of GND to V
1
X
and
2
X
Word Address
3
X
4
X
5
X
Unlike SWP and CWP, a V
pin to execute PWP. The state of A2, A1, and A0 is user
selectable. However, the address pin states need to
match the slave address bits, as shown in
6
X
Note:
7
X
MCP98243
8
X
Once the Permanent Write-Protect is
executed, it cannot be reversed, even if the
device power is cycled. See
for V
A
C
K
1
X
HV
2
X
voltage levels.
DD
3
X
Data
+ 1V to execute PWP.
4
X
MCP98243
HV
5
X
is not applied on the A0
6
X
7
X
MCP98243
DS22153A-page 39
8
X
A
C
K
Figure 2-13
Table
P
5-4.