M27C512-90XN6X STMicroelectronics, M27C512-90XN6X Datasheet - Page 8

• Manufacturer Part Number: M27C512-90XN6X
• Description: 512 Kbit 64Kb x8 UV EPROM and OTP EPROM
• Manufacturer: STMicroelectronics

M27C516
Figure 6. Programming and Verify Modes AC Waveforms
Figure 7. Programming Flowchart
8/12
YES
NO
FAIL
= 25
++n
V CC
A0-A14
Q0-Q15
V PP
E
P
G
V CC = 6.25V, V PP = 12.75V
CHECK ALL WORDS
NO
2nd: V CC = 4.2V
P = 100 s Pulse
1st: V CC = 6V
VERIFY
n = 0
Addr
Last
YES
YES
NO
tVCHPL
tVPHPL
tQVPL
tAVPL
tELPL
tPLPH
++ Addr
DATA IN
AI00707C
PROGRAM
VALID
tPHQX
PRESTO II Programming Algorithm
PRESTO II Programming Algorithm allows to pro-
gram the whole array with a guaranteedmargin, in
a typical time of 3 seconds. Programming with
PRESTO II involves the application of a sequence
of 100 s programpulses to each byte until a correct
verify occurs (see Figure 7). During programming
and verify operation, a MARGIN MODE circuit is
automatically activated in order to guarantee that
each cell is programmed with enough margin. No
overprogram pulse is applied since the verify in
MARGIN MODE provides necessary margin to
each programmed cell.
Program Inhibit
Programming of multiple M27C516sin parallelwith
different data is also easily accomplished. Except
for E, all like inputs including G of the parallel
M27C516 may be common. A TTL low level pulse
applied to a M27C516’s P input, with E low and V
at 12.75V,will program that M27C516. A high level
E input inhibits the other M27C516s from being
programmed.
Program Verify
A verify (read) should be performed on the pro-
grammed bits to determine that they were correctly
programmed. The verify is accomplished with E
and G at V
6.25V.
tQXGL
VERIFY
tGLQV
DATA OUT
IL
, P at V
IH
, V
PP
tGHQZ
tGHAX
at 12.75V and V
AI00936
CC
PP
at