MB82DP04184E-65L Datasheet, PDF (5/31 Pages) Fujitsu Component Limited. – 64M Bit (4 M word × 16 bit) Mobile Phone Application Specific Memory

MB82DP04184E-65L
■ POWER DOWN
• Power Down
The Power Down is low power idle state controlled by CE2. CE2 Low drives the device in Power Down mode
and maintains low power idle state as long as CE2 is kept Low. CE2 High resumes the device from Power Down
mode.
This device has three Power Down modes, Sleep, 8M-bit Partial and 16M-bit Partial. The selection of Power
Down mode can be programmed by series of read/write operation. Each mode has following data retention
features.
Mode
Data Retention
Retention Address
Sleep (default)
No
N/A
8M-bit Partial
8M bits
000000h to 07FFFFh
16M-bit Partial
16M bits
000000h to 0FFFFFh
The default state is Sleep and it is the lowest power consumption but all data will be lost once CE2 is brought
to Low for Power Down. It is not required to program to Sleep mode after power-up.
• Power Down Program Sequence
The program requires total six read/write operations with unique address and data. The device should be in
standby mode in the interval between each read/write operation. The following table shows the detail sequence.
Cycle #
Operation
Address
Data
1st
Read
3FFFFFh (MSB)
Read Data (RDa)
2nd
Write
3FFFFFh
RDa
3rd
Write
3FFFFFh
RDa
4th
Write
3FFFFFh
FFFFh
5th
Write
3FFFFFh
Data Key
6th
Write
3FFFFFh
FFFFh
The first cycle is to read from most significant address (MSB).
The second and third cycles are to write to MSB. If the second or third cycle is written into the different address,
the program is cancelled and the data written by the second or third cycle is valid as a normal write operation.
It is recommended to write back the data (RDa) read by first cycle to MSB in order to secure the data.
The fourth to sixth cycles are to write to MSB. The data of fourth and sixth cycles must be “FFFFh” and data of
fifth cycle are specific data key for mode selection. If the fourth to sixth cycles are written into different address,
the program is also cancelled but write data may not be written as normal write operation.
Once this program sequence is performed from a Partial mode to the other Partial mode, the written data stored
in memory cell array may be lost. Therefore, this program should be performed prior to regular read/write
operation if Partial Power Down mode is used.
• Data Key
The data key has following format.
Mode
Sleep (default)
8M-bit Partial
16M-bit Partial
DQ15 to DQ2
1
1
1
Data
DQ1
DQ0
1
1
0
1
0
0
Hexadecimal
FFFFh
FFFDh
FFFCh
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