AdvancedCAT28C512/513
10
Doc. No. 25074-00 2/98
To activate the software data protection, the device must
be sent three write commands to specific addresses with
specific data (Figure 9). This sequence of commands
(along with subsequent writes) must adhere to the page
write timing specifications (Figure 11). Once this is done,
all subsequent byte or page writes to the device must be
preceded by this same set of write commands. The data
protection mechanism is activated until a deactivate
sequence is issued regardless of power on/off transi-
tions. This gives the user added inadvertent write pro-
tection on power-up in addition to the hardware protec-
tion provided.
To allow the user the ability to program the device with
an E
2
PROM programmer (or for testing purposes) there
is a software command sequence for deactivating the
data protection. The six step algorithm (Figure 10) will
reset the internal protection circuitry, and the device will
return to standard operating mode (Figure 12 provides
reset timing). After the sixth byte of this reset sequence
has been issued, standard byte or page writing can
commence.
Figure 11. Software Data Protection Timing
5096 FHD F13
CE
WE
t
WP
AA
5555
55
2AAA
A0
5555
DATA
ADDRESS
t
BLC
t
WC
BYTE OR
PAGE
WRITES
ENABLED
Figure 12. Resetting Software Data Protection Timing
CE
WE
AA
5555
55
2AAA
DATA
ADDRESS
t
WC80
5555
AA
5555
55
2AAA
20
5555
SDP
RESET
DEVICE
UNPROTECTED
ORDERING INFORMATION
Notes:
(1) The device used in the above example is a CAT28C512HNI-15T (100,000 Cycle Endurance, PLCC, Industrial temperature, 150 ns
Access Time, Tape & Reel).
(2) 28C513 is offered only in PLCC package.
28C512/513 F16
5096 FHD F14
Speed
12: 120ns
15: 150ns
Prefix Device # Suffix
28C512
Product
Number
28C512
28C513
CAT
Optional
Company
ID
NI T
Tape & Reel
T: 500/Reel
Package
P: PDIP
N: PLCC
T14: TSOP (10mmx14mm)
T: TSOP (8mmX20mm)
-15
Temperature Range
Blank = Commercial (0˚C to +70˚C)
I = Industrial (-40˚C to +85˚C)
A = Automotive (-40˚ to +105˚C)*
H
Endurance
Blank = 10,000 Cycle
H = 100,000 Cycle
* -40˚C to +125˚C is available upon request
