k4h281638l Samsung Semiconductor, Inc., k4h281638l Datasheet - Page 23

• Manufacturer Part Number: k4h281638l
• Description: 128mb L-die Ddr Sdram
• Manufacturer: Samsung Semiconductor, Inc.

K4H281638L
Component Notes
17. For CK & CK slew rate ≥ 1.0 V/ns
18. These parameters guarantee device timing, but they are not necessarily tested on each device. They may be guaranteed by
19. Slew Rate is measured between V
20. Min (tCL, tCH) refers to the smaller of the actual clock low time and the actual clock high time as provided to the device (i.e. this
21. tQH = tHP - tQHS, where:
22. tDQSQ
23. tDAL = (tWR/tCK) + (tRP/tCK)
device design or tester correlation.
Consists of data pin skew and output pattern effects, and p-channel to n-channel variation of the output drivers for any given cycle.
value can be greater than the minimum specification limits for tCL and tCH).....For example, tCL and tCH are = 50% of the
period, less the half period jitter (tJIT(HP)) of the clock source, and less the half period jitter due to crosstalk (tJIT(crosstalk)) into
the clock traces.
case pull-in of DQ on the next transition, both of which are, separately, due to data pin skew and output pattern effects, and p-
channel to n-channel variation of the output drivers.
For each of the terms above, if not already an integer, round to the next highest integer. Example: For DDR400 at CL=3 and
tCK=5ns tDAL = (15 ns / 5 ns) + (15 ns/ 5 ns) = (3) + (3)
tDAL = 6 clocks
tHP = minimum half clock period for any given cycle and is defined by clock high or clock low (tCH, tCL). tQHS accounts for 1) The
pulse duration distortion of on-chip clock circuits; and 2) The worst case push-out of DQS on one tansition followed by the worst
OH
(AC) and V
OL
(AC).
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Rev. 1.1 October 2008
DDR SDRAM