M27W064-110N1T STMicroelectronics, M27W064-110N1T Datasheet - Page 8

• Manufacturer Part Number: M27W064-110N1T
• Description: 64 Mbit 4Mb x16 3V Supply FlexibleROM Memory
• Manufacturer: STMicroelectronics

M27W101
Figure 6. Programming and Verify Modes AC Waveforms
Figure 7. Programming Flowchart
8/15
YES
NO
FAIL
= 25
++n
V CC
A0-A16
Q0-Q7
V PP
E
P
G
V CC = 6.25V, V PP = 12.75V
CHECK ALL BYTES
NO
2nd: V CC = 2.7V
P = 100 s Pulse
1st: V CC = 5V
VERIFY
n = 0
Addr
Last
YES
YES
tVPHPL
tVCHPL
NO
tAVPL
tELPL
tQVPL
tPLPH
++ Addr
DATA IN
PROGRAM
AI00715D
VALID
tPHQX
PRESTO II Programming Algorithm
PRESTO II Programming Algorithm allows the
whole array to be programmed, with a guaranteed
margin, in a typical time of 13 seconds. Program-
ming with PRESTO II involves in applying a se-
quence of 100 s program pulses to each byte until
a correct verify occurs (see Figure 7). During pro-
gramming and verify operation, a MARGIN MODE
circuit is automatically activated in order to guar-
antee that each cell is programmed with enough
margin. No overprogram pulse is applied since the
verify in MARGIN MODE at V
3.6V, provides necessary margin to each pro-
grammed cell.
Program Inhibit
Programming of multiple M27W101s in parallel
with different data is also easily accomplished. Ex-
cept for E, all like inputs including G of the parallel
M27W101 may be common. A TTL low level pulse
applied to a M27W101’s P input, with E low and
V
level E input inhibits the other M27W101s from be-
ing programmed.
Program Verify
A verify (read) should be performed on the pro-
grammed bits to determine that they were correct-
ly programmed. The verify is accomplished with E
and G at V
6.25V.
tQXGL
PP
at 12.75V, will program that M27W101. A high
VERIFY
tGLQV
DATA OUT
IL
, P at V
IH
, V
PP
tGHQZ
tGHAX
at 12.75V and V
CC
AI00714
much higher than
CC
at