Rainbow Electronics AT27LV520 - Manual (Page 9)

AT27LV520
9
Rapid
™
Programming Algorithm
A 50 µs ALE pulse width is used to program. The address
is set to the first location. V
CC
is raised to 6.5V and OE/V
PP
is raised to 13.0V. Each address is first programmed with
one 50 µs ALE pulse without verification. Then a verifica-
tion/reprogramming loop is executed for each address. In
the event a byte fails to pass verification, up to 10 succes-
sive 50 µs pulses are applied with a verification after each
pulse. If the byte fails to verify after 10 pulses have been
applied, the part is considered failed. After the byte verifies
properly, the next address is selected until all have been
checked. OE/V
PP
is then lowered to V
IH
and V
CC
to 5.0V. All
bytes are read again and compared with the original data to
determine if the device passes or fails.
START
ADDR = FIRST LOCATION
ADDR = FIRST LOCATION
VCC = 6.5V
VPP = 13.0V
VCC = 5.0V
VPP = 5.0V
PROGRAM ONE 50 µS PULSE
PROGRAM ONE 50 µS PULSE
LAST
ADDR.?
LAST
ADDR.?
NO
NO
NO
X = 0
X = 10?
INCREMENT X
VERIFY
BYTE
DEVICE
FAILED
DEVICE
PASSED
COMPARE
ALL BYTES
TO ORIGINAL
DATA
YES
YES
YES
INCREMENT ADDRESS
INCREMENT ADDRESS
PASS
PASS
FAIL
FAIL