
HM628128DI Series
8
Write Cycle
HM628128DI
-7
Parameter
Symbol
Min
Max
Unit
Notes
Write cycle time
t
WC
t
AW
t
CW
t
WP
t
AS
t
WR
t
DW
t
DH
t
OW
t
OHZ
t
WHZ
70
—
ns
Address valid to end of write
60
—
ns
Chip selection to end of write
60
—
ns
5
Write pulse width
50
—
ns
4, 13
Address setup time
0
—
ns
6
Write recovery time
0
—
ns
7
Data to write time overlap
30
—
ns
Data hold from write time
0
—
ns
Output active from output in high-Z
5
—
ns
2
Output disable to output in high-Z
WE
to output in high-Z
Notes: 1. t
, t
and t
are defined as the time at which the outputs achieve the open circuit conditions
and are not referred to output voltage levels.
2. This parameter is sampled and not 100% tested.
3. At any given temperature and voltage condition, t
HZ
max is less than t
LZ
min both for a given device
and from device to device.
4. A write occurs during the overlap (t
) of a low
CS1
, a high CS2, and a low
WE
. A write begins at
the latest transition among
CS1
going low, CS2 going high, and
WE
going low. A write ends at the
earliest transition among
CS1
going high, CS2 going low, and
WE
going high. t
WP
is measured
from the beginning of write to the end of write.
5. t
CW
is measured from
CS1
going low or CS2 going high to the end of write.
6. t
AS
is measured from the address valid to the beginning of write.
7. t
is measured from the earlier of
WE
or
CS1
going high or CS2 going low to the end of write
cycle.
8. During this period, I/O pins are in the output state; therefore, the input signals of the opposite phase
to the outputs must not be applied.
9. If the
CS1
goes low or CS2 going high simultaneously with
WE
going low or after
WE
going low,
the output remain in a high impedance state.
10.Dout is the same phase of the write data of this write cycle.
11.Dout is the read data of next address.
12.If
CS1
is low and CS2 high during this period, I/O pins are in the output state. Therefore, the input
signals of the opposite phase to the outputs must not be applied to them.
13.In the write cycle with
OE
low fixed, t
WP
must satisfy the following equation to avoid a problem of
data bus contention. t
WP
≥
t
DW
min + t
WHZ
max
0
25
ns
1, 2, 8
0
25
ns
1, 2, 8