m34e02 STMicroelectronics, m34e02 Datasheet - Page 13

• Manufacturer Part Number: m34e02
• Description: 2 Kbit Serial I?c Bus Eeprom With Permanent And Reversible, Software Write Protection
• Manufacturer: STMicroelectronics

M34E02
3.5
Memory addressing
To start communication between the bus master and the slave device, the bus master must
initiate a Start condition. Following this, the bus master sends the Device Select Code,
shown in
The Device Select Code consists of a 4-bit Device Type Identifier, and a 3-bit Chip Enable
“Address” (E2, E1, E0). To address the memory array, the 4-bit Device Type Identifier is
1010b; to access the write-protection settings, it is 0110b.
Up to eight memory devices can be connected on a single I
unique 3-bit code on the Chip Enable (E0, E1, E2) inputs. When the Device Select Code is
received, the device only responds if the Chip Enable Address is the same as the value on
the Chip Enable (E0, E1, E2) inputs.
The 8
If a match occurs on the Device Select code, the corresponding device gives an
acknowledgment on Serial Data (SDA) during the 9
the Device Select code, it deselects itself from the bus, and goes into Standby mode.
Table 3.
1. X =
Figure 6.
Current Address Read
Random Address Read
Sequential Read
Byte Write
Page Write
th
V
IH
bit is the Read/Write bit (RW). This bit is set to 1 for Read and 0 for Write operations.
Mode
or V
Table 2
Memory
IL
Operating modes
Result of setting the write protection
.
Area
(on Serial Data (SDA), most significant bit first).
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
th
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
bit time. If the device does not match
State of the EEPROM memory
area after write access
to the Protect Register
2
Protected
Standard
C bus. Each one is given a
Array
Array
Write
Initial Sequence
FFh
80h
7Fh
00h
Device operation
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