AT27C520

8

A 50

µs ALE pulse width is used to program. The address

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

bytes are read again and compared with the original data to

determine if the device passes or fails.

V

= 5.0V

CC

V

= 6.5V

CC

V

= 13.0V

PP

ALL BYTES

COMPARE

DATA

TO ORIGINAL

PASSED

DEVICE

DEVICE

FAILED

FAIL

PASS

ADDR = FIRST LOCATION

START

X = 0

PROGRAM ONE 50 S PULSE

µ

INCREMENT X

YES

VERIFY

BYTE

X = 10?

FAIL

PASS

ADDR = FIRST LOCATION

ADDR.?

LAST

ADDRESS

INCREMENT

NO

YES

PROGRAM ONE 100 S PULSE

µ

NO

INCREMENT

ADDRESS

LAST

ADDR.?

YES

V = 5.0V

PP

NO