X20C05
PIN DESCRIPTIONS
Addresses (A0–A8)
Nonvolatile Enable (NE)
The Nonvolatile Enable input controls the recall function
2
to the E PROM array.
The Address inputs select an 8-bit memory location
during a read or write operation.
AUTOSTORE Output (AS)
AS is an open drain output which, when asserted indi-
Chip Enable (CE)
cates V has fallen below the AUTOSTORE threshold
CC
(V
). AS may be wire-ORed with multiple open drain
The Chip Enable input must be LOW to enable all read/
writeoperations.WhenCEisHIGH,powerconsumption
is reduced.
ASTH
outputsandusedasaninterruptinputtoamicrocontroller.
PIN NAMES
Output Enable (OE)
TheOutputEnableinputcontrolsthedataoutputbuffers
and is used to initiate read and recall operations. Output
Enable LOW disables a store operation regardless of
the state of CE, WE, or NE.
Symbol
A –A
Description
Address Inputs
Data Input/Output
Write Enable
Chip Enable
0
8
I/O –I/O
0
7
WE
CE
OE
NE
AS
Data In/Data Out (I/O0–I/O7)
Data is written to or read from the X20C05 through the
I/O pins. The I/O pins are placed in the high impedance
statewheneither CE or OE isHIGHorwhen NE isLOW.
Output Enable
Nonvolatile Enable
AUTOSTORE Output
+5V
Write Enable (WE)
The Write Enable input controls the writing of data to the
RAM.
V
CC
V
SS
Ground
NC
No Connect
3827 PGM T01
FUNCTIONAL DIAGRAM
V
SENSE
AS
CC
EEPROM ARRAY
ROW
SELECT
RECALL
HIGH SPEED
512 x 8
A –A
3
6
SRAM
ARRAY
ORE
ST
CE
OE
WE
NE
CONTROL
LOGIC
COLUMN
SELECT
&
A –A
0
2
A –A
7
8
I/OS
3827 FHD F01
I/O –I/O
0
7
2
XICOR [ XICOR INC. ]
