Internet Data Sheet
HY[B/I]18T256[40/80/16]0B[C/F](L)
256-Mbit Double-Data-Rate-Two SDRAM
Symbol
Parameter
Description
Units
tERR.nPER
Cumulative error
across n cycles
t
ERR.2PER is defined as the cumulative error across n consecutive cycles ps
from tCK.AVG
:
i + n – 1
⎛
⎜
⎜
⎝
⎞
⎟
tERR(nper) =
tCKj – n × tCK(avg)
(3)
∑
⎟
⎠
j = i
where, i = 1 to 200 and
n = 3 for tERR.3PER
n = 4 for tERR.4PER
n = 5 for tERR.5PER
6 ≤ n ≤ 10 for tERR.6-10PER
11 ≤ n ≤ 50 for tERR.11-50PER
tCH.AVG
tCL.AVG
tJIT.DUTY
Average high-pulse
width
tCH.AVG is defined as the average high-pulse width, as calculated across tCK.AVG
any consecutive 200 high pulses:
N
⎛
⎜
⎜
⎝
⎞
⎟
1
.
----------------------------------------
tCH(avg) =
tCHj
(4)
∑
⎟
⎠
(N × tCK(avg))
j = 1
N = 200
Average low-pulse
width
tCL.AVG is defined as the average low-pulse width, as calculated across any tCK.AVG
consecutive 200 low pulses:
N
⎛
⎜
⎜
⎝
⎞
⎟
1
(5)
.
----------------------------------------
tCL(avg) =
tCLj
∑
⎟
⎠
(N × tCK(avg))
j = 1
N = 200
Duty-cycle jitter
t
t
t
t
t
JIT.DUTY = Min/Max of {tJIT.CH , tJIT.CL}, where:
ps
JIT.CH is the largest deviation of any single tCH from tCH.AVG
JIT.CL is the largest deviation of any single tCL from tCL.AVG
JIT.CH = {tCHi - tCH.AVG × tCK.AVG} where i=1 to 200
JIT.CL = {tCLi - tCL.AVG × tCK.AVG} where i=1 to 200
The following parameters are specified per their average values however, it is understood that the following relationship
between the average timing and the absolute instantaneous timing holds all the time.
Rev. 1.11, 2007-07
60
11172006-LBIU-F1TN
QIMONDA [ QIMONDA AG ]
