HYB18T512400B2C Datasheet, PDF (58/69 Pages) Qimonda AG – 512-Mbit Double-Data-Rate-Two SDRAM

Internet Data Sheet
HY[B/I]18T512[40/80/16]0B2[C/F](L)
512-Mbit Double-Data-Rate-Two SDRAM
Symbol
t_ERR.nPER
t_CH.AVG
t_CL.AVG
t_JIT.DUTY
Parameter
Cumulative error
across n cycles
Average high-pulse
width
Average low-pulse
width
Duty-cycle jitter
Description
Units
t_ERR.2PER is defined as the cumulative error across n consecutive cycles ps
from t_CK.AVG:
⎛^{i + n – 1}
⎞
tERR(nper)
=
⎜
⎜
∑
tCK_{j⎟⎟} – n × tCK(avg)
(3)
⎝ _j=i
⎠
where, i = 1 to 200 and
n = 3 for t_ERR.3PER
n = 4 for t_ERR.4PER
n = 5 for t_ERR.5PER
6 ≤ n ≤ 10 for t_ERR.6-10PER
11 ≤ n ≤ 50 for t_ERR.11-50PER
t_CH.AVG is defined as the average high-pulse width, as calculated across
any consecutive 200 high pulses:
t_CK.AVG
tCH(avg)
=
(^---N------×^{-----t--C---1-K-----}(^{--a---v---g----})^---) ^{. ⎜⎜⎛}
N
∑
⎞
tCH_{j⎟⎟}
(4)
⎝_{j = 1}
⎠
N = 200
t_CL.AVG is defined as the average low-pulse width, as calculated across any t_CK.AVG
consecutive 200 low pulses:
tCL(avg)
=
(^---N------×^{-----t--C---1-K-----}(^{--a---v---g----})^---)
⎛
.^⎜
⎜
N
∑
⎞
tCL_{j⎟⎟}
(5)
⎝_{j = 1} ⎠
N = 200
t_JIT.DUTY = Min/Max of {t_JIT.CH , t_JIT.CL}, where:
ps
t_JIT.CH is the largest deviation of any single t_CH from t_CH.AVG
t_JIT.CL is the largest deviation of any single t_CL from t_CL.AVG
t_JIT.CH = {t_CHi - t_CH.AVG × t_CK.AVG} where i=1 to 200
t_JIT.CL = {t_CLi - t_CL.AVG × t_CK.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. 1.12, 2007-05
58
10062006-YPTZ-CDR7