CAT1161 Catalyst Semiconductor, CAT1161 Datasheet - Page 6

• Manufacturer Part Number: CAT1161
• Description: Supervisory Circuits with I2C Serial CMOS EEPROM/ Precision Reset Controller and Watchdog Timer
• Manufacturer: Catalyst Semiconductor

Hardware Data Protection
The CAT1161/2 is designed with the following hardware
data protection features to provide a high degree of data
integrity.
(1) The CAT1161/2 features a WP pin. When the WP pin
is tied high the entire memory array becomes write
protected (read only).
(2) The V
falls below the reset threshold value (VTH). The V
out inhibits writes to the serial EEPROM whenever V
Figure 2. Bus Timing
CAT1161/2
Doc. No. 3002, Rev. D
Figure 3. Write Cycle Timing
Figure 4. Start/Stop Timing
SCL
SDA
CC
SDA OUT
SDA IN
sense provides write protection when V
SCL
SDA
SCL
t SU:STA
8TH BIT
BYTE n
t F
START BIT
t HD:STA
t LOW
ACK
t AA
t HD:DAT
t HIGH
CC
lock
CC
CC
STOP
CONDITION
t LOW
6
falls below (power down) VTH or until V
reset threshold (power up) V
the internal EEPROM is not recognized and an ACK will
not be sent on the SDA line when RESET or RESET
is active.
Reset Threshold Voltage
The CAT1161/2 is offered with five reset threshold
voltage ranges. They are 4.50-4.75V, 4.25-4.50V, 3.00-
3.15V, 2.85-3.00V and 2.55-2.70V.
t DH
t SU:DAT
t R
t WR
STOP BIT
START
CONDITION
t SU:STO
t BUF
TH
. Any attempt to access
ADDRESS
CC
reaches the