9900-3003 5 1/11/00 CM
Xicor, Inc. 1994, 1995, 1996, 1998 Patents Pending
1
Characteristics subject to change without notice
Preliminary Information
64K
X46402
Functional Diagram
Command
Decode
and
Control
Logic
HV Generation
Timing and Control
X
Y Decoder
Data Register
Write Control
Password Logic
WP
SCL
SDA
Vcc
V2FAIL
(Vcc) Control Signal
V2MON
RESET
E
A
Write Password Area
(Bytes)
(64, 128, 256, 512,
2K, 4K, All, None)
POWER ON AND
LOW VOLTAGE
GENERATION
V
2TRIP
+
-
RESET
V
TRIP
+
-
RESET &
WATCHDOG
TIMEBASE
Control
OTP array 1
OTP array 2
WATCHDOG
TIMER RESET
Passwords
No Password Area
Dual Voltage CPU Supervisor with 64K Password Protected EEPROM
FEATURES
Dual Voltage Detection and Reset Assertion
—Low Vcc Monitor
—Low V2MON Monitor
—Low Vcc Block of EEPROM Writes
—RESET Signal Valid down to Vcc=1V
Selectable Watchdog Timer
—150ms, 450ms, 1s, 5s, 10s, 20s, 1min, OFF
Volatile Flag shows Watchdog/Low Voltage Reset
64kbit 2-wire Serial EEPROM
—1MHz Serial Interface speed
—64-Byte Page Write Mode
Two 64-Byte OTP memory blocks
—Requires 64-bit OTP password to write
Adjustable size Password Protected Array
—64 Bit Read and Write Array Passwords
—Non-password protected array area
8 count tamper counter for invalid passwords
Operates at 2.5-3.7V
8L TSSOP package
DESCRIPTION
The X46402 combines several functions into one device.
The first is a dual voltage CPU supervisor plus 64Kbit
serial EEPROM memory with password protected write
and read operations. The size of the password protected
area is selectable by 3 control bits. A Write Protect (WP)
pin in conjunction with a WPEN bit provides hardware
OTP control of the configuration of the array. Password
protected areas require 64 bit read or write passwords
prior to access. The eighth illegal password entry
(regardless of the number of correct entries) sets an OTP
tamper bit. This bit is one of the 32 bits in the Device ID.
A secondary voltage monitor circuit activates a V2FAIL
pin when the secondary supply voltage drops below a
V2trip voltage. This circuit is primarily intended to detect
the immediate loss of the battery supply.
A low Vcc voltage detect circuit activates a RESET pin
when Vcc drops below a V
TRIP
blocks read or write operations.
voltage. This signal also
A watchdog timer with the time period controlled by three
bits provides several possible time out periods from
150ms to 1 minute.