AC Write Characteristics
Table 8. AC Electrical Characteristics
Over the Full Operating Temperature and Supply Voltage Range
M
M
Write Cycle
67025-30
67025-45
Unit
Symbol (1)
TAVAVW
TELWH
TAVWH
TAVWL
TWLWH
TWHAX
TDVWH
TGHQZ
TWHDX
TWLQZ
TWHQX
TSWRD
TSPS
Symbol (2)
tWC
Parameter
Min.
Max.
–
Min.
Max.
–
Write cycle time
30
25
25
0
45
40
40
0
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
tSW
Chip select to end of write (3)
Address valid to end of write
Address Set-up Time
Write Pulse Width
–
–
tAW
–
–
tAS
–
–
tWP
25
0
–
35
0
–
tWR
Write Recovery Time
Data Valid to end of write
–
–
tDW
20
–
–
25
–
–
(5)
tHZ
Output high Z time (4)
15
–
20
–
tDH
Data hold time (6)
0
0
tWZ
Write enable to output in high Z (4) (5)
Output active from end of write (4) (5) (6)
SEM flag write to read time
SEM flag contention window
–
15
–
–
20
–
tOW
0
0
tSWRD
tSPS
10
10
–
10
10
–
–
–
1.
2.
3.
STD symbol.
ALT symbol.
To access RAM CS = VIL, UB or LB = VIL, SEM = VIH. To access semaphore CS = VIH, SEM = VIL. This condition must be valid
for entire tSW time.
4.
5.
6.
Transition is measured ± 500 mV from low or high impedance voltage with load (Figure 2 and Figure 3).
The parameters is guaranteed but not tested.
The specification fot tDH must be met by the device supplying write data to the RAM under all operating conditions. Although tDH
and tOW values will vary over voltage and temperature, the actual tDH will always be smaller than the actual tOW
.
15
M67025E
4146J–AERO–06/03
ATMEL [ ATMEL ]
