hm62256b ETC-unknow, hm62256b Datasheet - Page 8

• Manufacturer Part Number: hm62256b
• Description: 256k Sram 32-kword 8-bit
• Manufacturer: ETC-unknow

HM62256B Series
Write Cycle
Parameter
Write cycle time
Chip selection to end of write
Address setup time
Address valid to end of write
Write pulse width
Write recovery time
Write to output in high-Z
Data to write time overlap
Data hold from write time
Output active from end of write
Output disable to output in High-Z
Notes: 1. t
8
2. This parameter is sampled and not 100% tested.
3. Address must be valid prior to or simultaneously with CS going low.
4. A write occurs during the overlap of a low CS and a low WE. A write begins at the latest
5. t
6. t
7. t
8. During this period, I/O pins are in the output state; therefore, the input signals of the opposite
9. If CS goes low simultaneously with WE going low or after WE going low, the outputs remain in
10. Dout is the same phase of the latest written data in this write cycle.
11. Dout is the read data of next address.
12. If CS is low during this period, I/O pins are in the output state. Therefore, the input signals of the
13. In the write cycle with OE low fixed, t
and are not referred to output voltage levels.
transition of CS going low or WE going low. A write ends at the earliest transition of CS going
high or WE going high. t
phase to the outputs must not be applied.
the high impedance state.
opposite phase to the outputs must not be applied to them.
data bus contention.
t
CHZ
CW
AS
WR
WP
is measured from the address valid to the beginning of write.
, t
is measured from CS going low to the end of write.
is measured from the earliest of CS or WE going high to the end of write cycle.
OHZ
t
DW
min + t
and t
WHZ
WHZ
are defined as the time at which the outputs achieve the open circuit conditions
max
WP
is measured from the beginning of write to the end of write.
Symbol
t
t
t
t
t
t
t
t
t
t
t
WC
CW
AS
AW
WP
WR
WHZ
DW
DH
OW
OHZ
WP
HM62256B
-5
Min
55
40
0
40
35
0
0
25
0
5
0
must satisfy the following equation to avoid a problem of
Max
—
—
—
—
—
—
20
—
—
—
20
-7
Min
70
60
0
60
50
0
0
30
0
5
0
Max
—
—
—
—
—
—
25
—
—
—
25
-8
Min
85
75
0
75
55
0
0
35
0
5
0
Max
—
—
—
—
—
—
30
—
—
—
30
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Notes
5
6
4, 13
7
1, 2, 8
2
1, 2, 8