Preliminary Information
64K
8192 x 8 Bit
X24645
2
Advanced 2-Wire Serial E PROM with Block LockTM Protection
FEATURES
DESCRIPTION
2
• 2.7V to 5.5V Power Supply
The X24645 is a CMOS 65,536-bit serial E PROM,
internally organized 8192 x 8. The X24645 features a
serial interface and software protocol allowing opera-
tion on a simple two wire bus.
• Low Power CMOS
—Active Read Current Less Than 1mA
—Active Write Current Less Than 3mA
—Standby Current Less Than 1µA
• Internally Organized 8192 x 8
• New Programmable Block Lock Protection
—Software Write Protection
Two device select inputs (S , S ) allow up to four
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2
devices to share a common two wire bus.
A Write Protect Register at the highest address loca-
tion, 1FFFh, provides three new write protection
features: Software Write Protect, Block Write Protect,
and Hardware Write Protect. The Software Write
Protect feature prevents any nonvolatile writes to the
X24645 until the WEL bit in the write protect register is
set. The Block Write Protection feature allows the user
to individually write protect four blocks of the array by
programming two bits in the write protect register. The
Programmable Hardware Write Protect feature allows
—Programmable hardware Write Protect
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• Block Lock (0, 1/4, 1/2, or all of the E PROM
array)
• 2 Wire Serial Interface
• Bidirectional Data Transfer Protocol
• 32 Byte Page Write Mode
—Minimizes Total Write Time Per Byte
• Self Timed Write Cycle
—Typical Write Cycle Time of 5ms
• High Reliability
the user to install the X24645 with WP tied to V
,
CC
—Endurance: 100,000 Cycles
—Data Retention: 100 Years
• Available Packages
program the entire memory array in place, and then
enable the hardware write protection by programming
a WPEN bit in the write protect register. After this,
selected blocks of the array, including the write protect
register itself, are permanently write protected, as long
as WP remains HIGH.
—8-Lead PDIP
—8-Lead SOIC (JEDEC)
—14-Lead SOIC (JEDEC)
—20-Lead TSSOP
FUNCTIONAL DIAGRAM
WP
H.V. GENERATION
START CYCLE
TIMING &
CONTROL
V
V
CC
SS
WRITE PROTECT
REGISTER AND
LOGIC
START
STOP
SDA
LOGIC
CONTROL
LOGIC
SLAVE ADDRESS
REGISTER
+COMPARATOR
2
E PROM
256 X 256
XDEC
LOAD
WORD
INC
SCL
ADDRESS
COUNTER
S
S
2
1
R/W
YDEC
8
CK
D
OUT
PIN
DATA REGISTER
D
OUT
ACK
2783 ILL F01
Xicor, 1995, 1996 Patents Pending
2783-3.5 5/13/96 T1/C0/D0 NS
Characteristics subject to change without notice
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