Preliminary Information
Replaces X25163/X25165
X5163/X5165
CPU Supervisor with 16Kbit SPI EEPROM
FEATURES
• Selectable watchdog timer
• Low V
CC
detection and reset assertion
—Five standard reset threshold voltages
—Re-program low V
CC
reset threshold voltage
using special programming sequence
—Reset signal valid to V
CC
= 1V
• Determine watchdog or low voltage reset with a
volatile flag bit
• Long battery life with low power consumption
—<50µA max standby current, watchdog on
—<1µA max standby current, watchdog off
—<400µA max active current during read
• 16Kbits of EEPROM
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Protect 0, 1/4, 1/2 or all of EEPROM array with
Block Lock
™
protection
—In circuit programmable ROM mode
• 2MHz SPI interface modes (0,0 & 1,1)
• Minimize EEPROM programming time
—32-byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• 2.7V to 5.5V and 4.5V to 5.5V power supply
operation
• Available packages
—14-lead TSSOP, 8-lead SOIC
BLOCK DIAGRAM
Watchdog Transition
Detector
WP
SI
SO
SCK
CS/WDI
Data
Register
Command
Decode &
Control
Logic
V
CC
Threshold
Reset Logic
Protect Logic
RESET/RESET
Status
Register
EEPROM Array
4K Bits
4K Bits
8K Bits
Reset &
Watchdog
Timebase
X5163 = RESET
X5165 = RESET
Watchdog
Timer Reset
DESCRIPTION
These devices combine four popular functions, Power-
on Reset Control, Watchdog Timer, Supply Voltage
Supervision, and Block Lock Protect Serial EEPROM
Memory in one package. This combination lowers
system cost, reduces board space requirements, and
increases reliability.
Applying power to the device activates the power on
reset circuit which holds RESET/RESET active for a
period of time. This allows the power supply and oscilla-
tor to stabilize before the processor can execute code.
The Watchdog Timer provides an independent protection
mechanism for microcontrollers. When the microcon-
troller fails to restart a timer within a selectable time out
interval, the device activates the RESET/RESET signal.
The user selects the interval from three preset values.
Once selected, the interval does not change, even
after cycling the power.
The device’s low V
CC
detection circuitry protects the
user’s system from low voltage conditions, resetting the
system when V
CC
falls below the minimum V
CC
trip point.
RESET/RESET is asserted until V
CC
returns to proper
operating level and stabilizes. Five industry standard
V
TRIP
thresholds are available, however, Xicor’s unique
circuits allow the threshold to be reprogrammed to meet
custom requirements or to fine-tune the threshold for
applications requiring higher precision.
V
CC
V
TRIP
+
-
Power on and
Low Voltage
Reset
Generation
REV 1.1 3/5/01
www.xicor.com
Characteristics subject to change without notice.
1 of 21
XICOR [ XICOR INC. ]
