CAT1161/2
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
CC
sense provides write protection when V
CC
falls below the reset threshold value (VTH). The V
CC
lock
out inhibits writes to the serial EEPROM whenever V
CC
falls below (power down) VTH or until V
CC
reaches the
reset threshold (power up) V
TH
. Any attempt to access
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.
Figure 2. Bus Timing
tF
tLOW
SCL
tSU:STA
tHD:STA
tHD:DAT
tSU:DAT
tSU:STO
tHIGH
tLOW
tR
SDA IN
tAA
SDA OUT
tDH
tBUF
Figure 3. Write Cycle Timing
SCL
SDA
8TH BIT
BYTE n
ACK
tWR
STOP
CONDITION
START
CONDITION
ADDRESS
Figure 4. Start/Stop Timing
SDA
SCL
START BIT
STOP BIT
Doc. No. 3002, Rev. D
6
CATALYST [ CATALYST SEMICONDUCTOR ]
