V58C2128(804/404/164)S
NOTES: (continued)
23. The refresh period 64ms. This equates to an average refresh rate of 15.625µs.
24. The I/O capacitance per DQS and DQ byte/group will not differ by more than this maximum amount for any
given device.
t
t
t
t
25. The valid data window is derived by achieving other specifications - HP ( CK/2), DQSQ, and QH
t
t
t
( QH = HP - QHS). The data valid window derates directly porportional with the clock duty cycle and a practical data
valid window can be derived. The clock is allowed a maximum duty cycle variation of 45/55. Functionality is uncertain
when operating beyond a 45/55 ratio. The data valid window derating curves are provided below for duty cycles rang-
ing between 50/50 and 45/55.
26. Referenced to each output group: x4 = DQS with DQ0-DQ3; x8 = DQS with DQ0-DQ7; x16 = LDQS with DQ0-
DQ7; and UDQS with DQ8-DQ15.
27. This limit is actually a nominal value and does not result in a fail value. CKE is HIGH during REFRESH command
t
period ( RFC [MIN]) else CKE is LOW (i.e., during standby).
28. To maintain a valid level, the transitioning edge of the input must:
a) Sustain a constant slew rate from the current AC level through to the target AC level, VIL(AC) or VIH(AC).
b) Reach at least the target AC level.
c) After the AC target level is reached, continue to maintain at least the target DC level, VIL(DC) or VIH(DC).
29. The Input capacitance per pin group will not differ by more than this maximum amount for any given device..
30. CK and CK input slew rate must be •1V/ns.
31. DQ and DM input slew rates must not deviate from DQS by more than 10%. If the DQ/DM/DQS slew rate is less
t
t
than 0.5V/ns, timing must be derated: 50ps must be added to DS and DH for each 100mv/ns reduction in slew rate.
If slew rate exceeds 4V/ns, functionality is uncertain.
32. VDD must not vary more than 4% if CKE is not active while any bank is active.
3.8
3.750
3.700
3.6
3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
1.8
3.650
3.600
3.550
3.400
3.500
3.350
3.450
3.300
3.400
3.250
3.350
3.200
3.300
3.150
3.250
3.100
-7, -75 @tCK = 10ns
-8, @tCK = 10ns
3.050
3.000
2.950
2.900
-7, -75 @tCK = 7.5ns
-8, @tCK = 8ns
-7, @tCK = 7ns
2.500
2.463
2.425
2.388
2.350
2.313
2.275
2.238
2.200
2.163
2.125
50/50 49.5/50.5 49/51 48.5/52.5 48/52 47.5/53.5 47/53 46.5/54.5 46/54 45.5/55.5 45/55
NOTES: (continued)
V58C2128(804/404/164)S Rev. 1.6 March 2002
40
MOSEL [ MOSEL VITELIC, CORP ]
