W9425G6EH Datasheet, PDF (29/50 Pages) Winbond – 4 M × 4 BANKS × 16 BITS DDR SDRAM

W9425G6EH
(11) IF the result of nominal calculation with regard to tCK contains more than one decimal place, the result is rounded up to
the nearest decimal place.
(i.e., TDQSS = 0.75 × tCK, tCK = 7.5 nS, 0.75 × 7.5 nS = 5.625 nS is rounded up to 5.6 nS.)
(12) VX is the differential clock cross point voltage where input timing measurement is referenced.
(13) VID is magnitude of the difference between CLK input level and CLK input level.
(14) VISO means {VICK(CLK)+VICK( CLK )}/2.
(15) Refer to the figure below.
CLK
VX
CLK
VICK
VSS
VID(AC)
0 V Differential
VISO
VSS
VX
VICK
VISO(min)
VX
VICK
VX
VICK
VX
VID(AC)
VISO(max)
(16) tAC and tDQSCK depend on the clock jitter. These timing are measured at stable clock.
(17) A maximum of eight AUTO REFRESH commands can be posted to any given DDR SDRAM device.
(18) tDAL = (tWR/tCK) + (tRP/tCK)
(19) For command/address input slew rate ≥1.0 V/nS.
(20) For command/address input slew rate ≥0.5 V/nS and <1.0 V/nS.
(21) For CLK & CLK slew rate ≥1.0 V/nS (single--ended).
(22) These parameters guarantee device timing, but they are not necessarily tested on each device. They may be
guaranteed by device design or tester correlation.
(23) Slew Rate is measured between VOH(ac) and VOL(ac).
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Publication Release Date:Apr. 11, 2008
Revision A04