CAT28F020_04 Datasheet, PDF (13/15 Pages) Catalyst Semiconductor – 2 Megabit CMOS Flash Memory

CAT28F020
Abort/Reset
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.
POWER UP/DOWN PROTECTION
The CAT28F020 offers protection against inadvertent
programming during V_PP and V_CC power transitions.
When powering up the device there is no power-on
sequencing necessary. In other words, V_PP and V_CC
may power up in any order. Additionally V_PP may be
hardwired to V_PPH independent of the state of V_CC and
any power up/down cycling. The internal command
register of the CAT28F020 is reset to the Read Mode on
power up.
POWER SUPPLY DECOUPLING
To reduce the effect of transient power supply voltage
spikes, it is good practice to use a 0.1µF ceramic
capacitor between VCC and VSS and VPP and VSS. 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
VCC POWER-UP SETUP PROGRAM LATCH ADDRESS
& STANDBY
COMMAND
& DATA
PROGRAM
VERIFY
PROGRAMMING COMMAND
PROGRAM VCC POWER-DOWN/
VERIFICATION
STANDBY
ADDRESSES
WE (W)
tWC
tAVEL
tWLEL
tEHWH
tWC
tELAX
tWLEL
tEHWH
tWLEL
tRC
tEHWH
tEHQZ
OE (G)
CE (E)
DATA (I/O)
tGHEL
tEHEL
tEHEH
tDVEH
HIGH-Z
DATA IN
= 40H
tEHDX
tELEH
tELEH
tEHDX
tDVEH
tDVEH
DATA IN
VCC ^5.0V
0V
VPP ^VPPH
VPPL
tVPEL
tEHGL
DATA IN
= C0H
tOE
tEHDX
tOLZ
tLZ
tCE
tDF
tOH
VALID
DATA OUT
28F020 F09
28F020 F09
13
Doc. No. 1029, Rev. C