APPLICATION NOTE
A V A I LABLE
AN95 ā¢ AN103 ā¢ AN107
16K/64K/128K
X84161/641/129
ĀµPort Saver EEPROM
MPSā¢ EEPROM
FEATURES
ā¢ Up to 10MHz data transfer rate
ā¢ 25ns Read Access Time
ā¢ Direct Interface to Microprocessors and
Microcontrollers
āEliminates I/O port requirements
āNo interface glue logic required
āEliminates need for parallel to serial converters
ā¢ Low Power CMOS
ā1.8Vā3.6V, 2.5Vā5.5V and 5V Ā±10% Versions
āStandby Current Less than 1ĀµA
āActive Current Less than 1mA
ā¢ Byte or Page Write Capable
ā32-Byte Page Write Mode
ā¢ Typical Nonvolatile Write Cycle Time: 2ms
ā¢ High Reliability
ā100,000 Endurance Cycles
ā Guaranteed Data Retention: 100 Years
DESCRIPTION
The ĀµPort Saver memories need no serial ports or spe-
cial hardware and connect to the processor memory bus.
Replacing bytewide data memory, the ĀµPort Saver uses
bytewide memory control functions, takes a fraction of
the board space and consumes much less power.
Replacing serial memories, the ĀµPort Saver provides all
the serial beneļ¬ts, such as low cost, low power, low volt-
age, and small package size while releasing I/Os for
more important uses.
The ĀµPort Saver memory outputs data within 25ns of an
active read signal. This is less than the read access time
of most hosts and provides āno-wait-stateā operation.
This prevents bottlenecks on the bus. With rates to 10
MHz, the ĀµPort Saver supplies data faster than required
by most host read cycle speciļ¬cations. This eliminates
the need for software NOPs.
The ĀµPort Saver memories communicate over one line of
the data bus using a sequence of standard bus read and
write operations. This ābit serialā interface allows the
ĀµPort Saver to work well in 8-bit, 16 bit, 32-bit, and 64-bit
systems.
A Write Protect (WP) pin prevents inadvertent writes to
the memory.
Xicor EEPROMs are designed and tested for applica-
tions requiring extended endurance. Inherent data reten-
tion is greater than 100 years.
BLOCK DIAGRAM
System Connection
Ports
Saved
ĀµP
A15
ĀµC
DSP
A0
D7
ASIC
RISC
D0
P0/CS
P1/CLK
OE
P2/DI
P3/DO
WE
Ā©Xicor, Inc. 1994, 1997Patents Pending
7008-1.2 8/26/97 T2/C0/D0 SH
Internal Block Diagram
MPS
WP
H.V. GENERATION
TIMING & CONTROL
CE
COMMAND
I/O
DECODE
OE
AND
CONTROL
LOGIC
WE
X
DEC
EEPROM
ARRAY
16K x 8
8K x 8
2K x 8
Y DECODE
DATA REGISTER
7008 FRM F02.1
1
Characteristics subject to change without notice