m34e02 STMicroelectronics, m34e02 Datasheet - Page 20

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

Initial delivery state
4
5
5.1
5.1.1
20/33
Initial delivery state
The device is delivered with all bits in the memory array set to ‘1’ (each Byte contains FFh).
Use within a DDR2 DIMM
In the application, the M34E02 is soldered directly in the printed circuit module. The three
Chip Enable inputs (E0, E1, E2) must be connected to V
using a pull-up or pull-down resistor) through the DIMM socket (see
resistors needed for normal behavior of the I
mother-board (as shown in
The Write Control (WC) of the M34E02 can be left unconnected. However, connecting it to
V
Table 4.
Programming the M34E02
The situations in which the M34E02 is programmed can be considered under two headings:
DDR2 DIMM isolated
With specific programming equipment, it is possible to define the M34E02 content, using
Byte and Page Write instructions, and its write-protection using the SWP and CWP
instructions. To issue the SWP and CWP instructions, the DDR2 DIMM must be inserted in
the DDR2-specific slot where the E0 signal can be driven to V
instruction. This programming step is mainly intended for use by DDR2 DIMM makers,
whose end application manufacturers will want to clear this write-protection with the CWP
on their own specific programming equipment, to modify the lower 128 Bytes, and finally to
set permanently the write-protection with the PSWP instruction.
SS
is recommended, to maintain full read and write access.
when the DDR2 DIMM is isolated (not inserted on the PCB motherboard)
when the DDR2 DIMM is inserted on the PCB motherboard
DIMM Position
DRAM DIMM Connections
0
1
2
3
4
5
6
7
Figure
11).
V
V
V
V
V
V
V
V
E2
CC
CC
CC
CC
SS
SS
SS
SS
2
C bus are connected on the I
SS
V
V
V
V
V
V
V
V
or V
E1
CC
CC
CC
CC
SS
SS
SS
SS
HV
CC
during the whole
directly (that is without
Table
4). The pull-up
2
C bus of the
V
V
V
V
V
V
V
V
E0
CC
CC
CC
CC
SS
SS
SS
SS
M34E02