Am28F256A 29
AC CHARACTERISTICS—WRITE/ERASE/PROGRAM OPERATIONS
Alternate CE
# Controlled Writes
Notes:
1. Read timing characteristics during read/write operations are the same as during read-only operations. Refer to AC
Characteristics for Read Only operations.
2. Embedded program operation of 14 µs consists of 10 µs program pulse and 4 µs write recovery before read. This is the
minimum time for one pass through the programming algorithm.
3. Embedded erase operation of 5 sec consists of 4 sec array pre-programming time and one sec array erase time. This is a
typical time for one embedded erase operation.
4. Not 100% tested.
Parameter Symbols
Parameter Descr ipti on
Am28F256A Speed Options
UnitJEDEC Standard -70 -90 -120 -150 -200
t
AVAV
t
WC
Write Cycle Time (Note 4) Min 70 90 120 150 200 ns
t
AVEL
t
AS
Address Set up Tim e M in 0 0 0 0 0 ns
t
ELAX
t
AH
Address Hold Time Min 45 45 50 60 75 ns
t
DVEH
t
DS
Data Setup Time Min 45 45 50 50 50 ns
t
EHDX
t
g
Data Hold Time Min 10 10 10 10 10 ns
t
OEH
Output Enable Hold Time for
Embedded Algorithm only
Min1010101010ns
t
GHEL
Read Recovery Time Before Write Min 0 0 0 0 0 µs
t
WLEL
t
WS
WE# Setup Time by CE# Min00000ns
t
EHWK
t
WH
WE# Hold Time Min 0 0 0 0 0 ns
t
ELEH
t
CP
Write Pul se Wid th Min 65 65 70 80 80 ns
t
EHEL
t
CPH
Write Pul s e Wid th HIG H Min 20 20 20 20 20 ns
t
EHEH3
Embedded Programming Operation
(Note 2)
Min1414141414µs
t
EHEH4
Embedded Erase Operation (Note 3) Typ 5 5 5 5 5 sec
t
VPEL
V
PP
Setup Time to Chip Enable LOW
(Note 4)
Min 100 100 1 00 10 0 100 ns
t
VCS
V
CC
Setup Time to Chip Enable LOW
(Note 4)
Min5050505050µs
t
VPPR
V
PP
Rise Time 90% V
PPH
(Note 4) Min 500 500 500 500 500 ns
t
VPPF
V
PP
Fall Time 90% V
PPL
(Note 4) Min 500 500 500 500 500 ns
t
LKO
V
CC
< V
LKO
to Reset (Note 4) Min 100 100 100 100 100 ns