CAT28F010
Program-Verify Mode
POWER UP/DOWN PROTECTION
A Program-verify cycle is performed to ensure that all
bits have been correctly programmed following each
byte programming operation. The specific address is
already latched from the write cycle just completed, and
stayslatcheduntiltheverifyiscompleted. TheProgram-
verify operation is initiated by writing C0H into the
command register. An internal reference generates the
necessary high voltages so that the user does not need
to modify VCC. Refer to AC Characteristics (Program/
Erase) for specific timing parameters.
The CAT28F010 offers protection against inadvertent
programming during VPP and VCC power transitions.
When powering up the device there is no power-on
sequencing necessary. In other words, VPP and VCC
may power up in any order. Additionally VPP may be
hardwired to VPPH independent of the state of VCC and
any power up/down cycling. The internal command
register of the CAT28F010 is reset to the Read Mode on
power up.
Abort/Reset
POWER SUPPLY DECOUPLING
An Abort/Reset command is available to allow the user
to safely abort an erase or program sequence. Two
consecutive program cycles with FFH on the data bus
will abort an erase or a program operation. The abort/
reset operation can interrupt at any time in a program or
erase operation and the device is reset to the Read
Mode.
To reduce the effect of transient power supply voltage
spikes, it is good practice to use a 0.1µF ceramic
capacitorbetweenVCC andVSS andVPP andVSS.These
high-frequency capacitors should be placed as close as
possible to the device for optimum decoupling.
Figure 8. Alternate A.C. Timing for Program 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
ELAX
AVEL
(W)
WE (E)
t
t
WLEL
EHWH
t
t
t
WLEL
EHWH
EHQZ
t
t
WLEL
EHWH
OE (G)
t
t
t
t
EHEH
EHGL
DF
GHEL
t
EHEL
CE (W)
(E)
t
t
t
ELEH
ELEH
EHDX
OE
t
t
t
t
t
EHDX
EHDX
OLZ
OH
t
t
t
DVEH
DVEH
DVEH
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 F10
Doc. No. 25005-0A 2/98 F-1
13
CATALYST [ CATALYST SEMICONDUCTOR ]
