CAT28F010
Erase Mode
Erase-Verify Mode
During the first Write cycle, the command 20H is written
into the command register. In order to commence the
eraseoperation, theidenticalcommandof20Hhastobe
written again into the register. This two-step process
ensures against accidental erasure of the memory con-
tents. The final erase cycle will be stopped at the rising
edge of WE, at which time the Erase Verify command
(A0H)issenttothecommandregister. Duringthiscycle,
the address to be verified is sent to the address bus and
latched when WE goes low. An integrated stop timer
allows for automatic timing control over this operation,
eliminating the need for a maximum erase timing speci-
fication. Refer to AC Characteristics (Program/Erase)
for specific timing parameters.
The Erase-verify operation is performed on every byte
after each erase pulse to verify that the bits have been
erased.
Programming Mode
The programming operation is initiated using the pro-
gramming algorithm of Figure 7. During the first write
cycle, the command 40H is written into the command
register. During the second write cycle, the address of
thememorylocationtobeprogrammedislatchedonthe
falling edge of WE, while the data is latched on the rising
edge of WE. The program operation terminates with the
next rising edge of WE. An integrated stop timer allows
forautomatictimingcontroloverthisoperation, eliminat-
ing the need for a maximum program timing specifica-
tion. Refer to AC Characteristics (Program/Erase) for
specific timing parameters.
Figure 6. A.C. Timing for Programming Operation
SETUP PROGRAM LATCH ADDRESS
POWER-UP
PROGRAM
VERIFY
COMMAND
PROGRAM
VERIFICATION
V
POWER-DOWN/
STANDBY
V
CC
CC
& STANDBY
COMMAND
& DATA
PROGRAMMING
ADDRESSES
t
t
t
WC
WC
RC
t
t
AS
AH
CE (E)
t
t
CH
CS
t
t
CH
EHQZ
t
t
CS
CH
OE (G)
t
GHWL
t
t
t
WHGL
DF
WHWH1
t
WPH
WE (W)
t
t
t
t
WP
WP
WP
OE
t
t
t
t
DH
DH
DH
OH
t
t
t
t
DS
DS
OLZ
DS
HIGH-Z
DATA IN
= 40H
DATA IN
= C0H
DATA (I/O)
DATA IN
VALID
DATA OUT
t
LZ
t
CE
5.0V
0V
V
CC
t
VPEL
V
V
PPH
PPL
V
PP
28F010 F08
Doc. No. 25005-0A 2/98 F-1
11
CATALYST [ CATALYST SEMICONDUCTOR ]
