STTS424E02BDA3E STMICROELECTRONICS [STMicroelectronics], STTS424E02BDA3E Datasheet - Page 30

• Manufacturer Part Number: STTS424E02BDA3E
• Description: Memory module temperature sensor with a 2 Kb SPD EEPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

SPD EEPROM operation
5.4
30/51
Table 21.
1. X =
Figure 10. Result of setting the write protection
Setting the write protection
The Write Control (WC) is tied Low, hence the write protection of the memory array is
dependent on whether software write-protection has been set.
Software write-protection allows the bottom half of the memory area (addresses 00h to 7Fh)
to be write protected irrespective of subsequent states of the Write Control (WC) signal.
Software write-protection is handled by three instructions:
●
●
●
The level of write-protection (set or cleared) that has been defined using these instructions,
remains defined even after a power cycle.
Current address read
Random address read
Sequential read
Byte write
Page write
SWP: Set write protection
CWP: Clear write protection
PSWP: Permanently set write protection
V
IH
Mode
or V
Memory
IL
Operating modes
.
Area
Default EEPROM memory area
state before write access
to the Protect Register
RW bit
Standard
Standard
Array
Array
1
0
1
1
0
0
WC
FFh
80h
7Fh
00h
V
V
X
X
X
X
IL
IL
(1)
Bytes
≤ 16
≥ 1
1
1
1
START, device select, RW = 1
START, device select, RW = 0, address
reSTART, device select, RW = 1
Similar to current or random address read
START, device select, RW = 0
START, device select, RW = 0
State of the EEPROM memory
area after write access
to the Protect Register
Protected
Standard
Array
Write
Array
Initial sequence
FFh
80h
7Fh
00h
AI01936C
STTS424E02