CAT28C010
Advanced Information
Toactivatethesoftwaredataprotection,thedevicemust
besentthreewritecommandstospecificaddresseswith
specific data (Figure 9). This sequence of commands
(along with subsequent writes) must adhere to the page
writetimingspecifications(Figure11).Oncethisisdone,
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 E2PROM 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
t
WC
DATA
ADDRESS
AA
5555
55
2AAA
A0
5555
BYTE OR
PAGE
CE
WRITES
ENABLED
t
t
BLC
WP
WE
5096 FHD F13
Figure 12. Resetting Software Data Protection Timing
t
DATA
ADDRESS
AA
5555
55
2AAA
80
5555
AA
5555
55
2AAA
20
5555
WC
SDP
RESET
CE
DEVICE
UNPROTECTED
WE
5096 FHD F14
ORDERING INFORMATION
Prefix
Device #
Suffix
CAT
28C010
H
N
I
-15
T
Tape & Reel
T: 500/Reel
Temperature Range
Product
Number
28C010
Blank = Commercial (0˚C to +70˚C)
I = Industrial (-40˚C to +85˚C)
A = Automotive (-40˚ to +105˚C)*
Optional
Company
ID
Endurance
Blank = 10,000 Cycle
H = 100,000 Cycle
Package
Speed
12: 120ns
15: 150ns
P: PDIP
N: PLCC
T14: TSOP (10mmx14mm)
T: TSOP (8mmX20mm)
* -40˚C to +125˚C is available upon request
Notes:
28C010 F16
(1) The device used in the above example is a CAT28C010HNI-15T (100,000 Cycle Endurance, PLCC, Industrial temperature, 150 ns
Access Time, Tape & Reel).
Doc. No. 25093-00 7/99 P-1
10
CATALYST [ CATALYST SEMICONDUCTOR ]
