AC Characteristics—Write/Erase/Program Operations
Parameter Symbols
Am28F256A Speed Options
JEDEC
Standard
Parameter Description
Write Cycle Time (Note 4)
-70
70
0
-90
90
0
-120
120
0
-150
150
0
-200
200
0
Unit
ns
t
t
Min
Min
Min
Min
Min
AVAV
WC
t
t
Address Setup Time
Address Hold Time
Data Setup Time
Data Hold Time
ns
AVWL
WLAX
DVWH
WHDX
AS
AH
DS
DH
t
t
45
45
10
45
45
10
50
60
75
ns
t
t
t
50
50
50
ns
t
10
10
10
ns
Output Enable Hold Time for
Embedded Algorithm only
t
Min
Min
Min
10
0
10
0
10
0
10
0
10
0
ns
µs
ns
OEH
t
Read Recovery Time before Write
GHWL
Chip Enable Embedded Algorithm
Setup Time
t
t
20
20
20
20
20
ELWLE
CSE
t
t
Chip Enable Hold Time
Write Pulse Width
Min
Min
Min
0
0
0
0
0
ns
ns
ns
WHEH
WLWH
WHWL
CH
t
t
45
20
45
20
50
20
60
20
60
20
WP
t
t
Write Pulse Width HIGH
WPH
Embedded Programming Operation
(Note 2)
t
t
Min
Typ
Min
14
5
14
5
14
5
14
5
14
5
µs
sec
ns
WHWH3
WHWH4
Embedded Erase Operation (Note 3)
V
Setup Time to Chip Enable LOW
PP
t
100
100
100
100
100
VPEL
(Note 4)
V
Setup Time to Chip Enable LOW
CC
t
Min
50
50
50
50
50
µs
VCS
(Note 4)
t
V
V
V
Rise Time 90% V (Note 4)
PPH
Min
Min
Min
500
500
100
500
500
100
500
500
100
500
500
100
500
500
100
ns
ns
ns
VPPR
PP
PP
CC
t
Fall Time 90% V
(Note 4)
VPPF
PPL
t
< V
to Reset (Note 4)
LKO
LKO
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 1 sec array erase time. This is a typical
time for one embedded erase operation.
4. Not 100% tested.
Am28F256A
25