X20C04
PIN DESCRIPTIONS
Addresses (A0–A8)
Write Enable (WE)
The Write Enable input controls the writing of data to
both the static RAM and stores to the E2PROM.
The Address inputs select an 8-bit memory location
during a read or write operation.
Nonvolatile Enable (NE)
The Nonvolatile Enable input controls all accesses to
the E2PROM array (store and recall functions).
Chip Enable (CE)
The Chip Enable input must be LOW to enable all read/
writeoperations.WhenCEisHIGH,powerconsumption
is reduced.
PIN NAMES
Symbol
A –A
Description
Address Inputs
Data Input/Output
Write Enable
Chip Enable
Output Enable
Nonvolatile Enable
+5V
0
8
Output Enable (OE)
I/O –I/O
0
7
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.
WE
CE
OE
NE
Data In/Data Out (I/O0–I/O7)
V
CC
V
SS
Data is written to or read from the X20C04 through the
I/O pins. The I/O pins are placed in the high impedance
statewheneither CEor OEisHIGHorwhen NEisLOW.
Ground
NC
No Connect
3825 PGM T01
FUNCTIONAL DIAGRAM
V
SENSE
CC
EEPROM ARRAY
ROW
SELECT
RECALL
512 x 8
SRAM
A –A
3
6
ARRAY
ORE
ST
CE
OE
WE
NE
CONTROL
LOGIC
COLUMN
SELECT
&
A –A
0
2
A –A
7
8
I/OS
3825 FHD F01
I/O –I/O
0
7
2
XICOR [ XICOR INC. ]
