Datasheet

- t
JIT
(per), t
JIT
(per,lck)
t
JIT
(per) is defined as the largest deviation of any single tCK from t
CK
(avg).
t
JIT
(per) = Min/max of {t
CKi
- t
CK
(avg) where i=1 to 200}
t
JIT
(per) defines the single period jitter when the DLL is already locked.
t
JIT
(per,lck) uses the same definition for single period jitter, during the DLL locking period only.
t
JIT
(per) and
tJIT
(per,lck) are not guaranteed through final production testing.
- t
JIT
(cc), t
JIT
(cc,lck)
t
JIT
(cc) is defined as the difference in clock period between two consecutive clock cycles:
t
JIT
(cc) = Max of |t
CKi
+1 – t
CKi
|
t
JIT
(cc) defines the cycle to cycle jitter when the DLL is already locked.
t
JIT
(cc,lck) uses the same definition for cycle to cycle jitter, during the DLL locking period only.
t
JIT
(cc) and tJIT(cc,lck) are not guaranteed through final production testing.
- t
ERR
(2per), t
ERR
(3per), t
ERR
(4per), t
ERR
(5per), t
ERR
(6-10per) and t
ERR
(11-50per)
t
ERR
is defined as the cumulative error across multiple consecutive cycles from t
CK
(avg).
( ) ( )
( )
+−
=
⎡⎤
=−×
⎢⎥
⎣⎦
∑
j
1
ERR CK CK
1
nper
ttt
iN
j
Navg
where
( )
( )
( )
( )
( )
( )
⎧
⎪
⎪
⎪
⎪
⎨
⎪
⎪
≤≤ −
⎪
⎪
≤≤ −
⎩
ERR
ERR
ERR
ERR
ERR
ERR
n=2 for 2
n=3 for 3
n=4 for 4
n=5 for 5
6 n 10 for 6 10
11 n 50 for 11 50
t
t
t
t
t
t
per
per
per
per
per
per
NOTE
34: These 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 at all times. (Min
andmax of SPEC values are to be used for calculations in the table below.)
Table 31. Absolute clock period average values
Parameter
Symbol
Min.
Max.
Units
Absolute clock period
t
CK
(abs)
t
CK
(avg),min + t
JIT
(per),min
t
CK
(avg),max + t
JIT
(per),max
ps
Absolute clock HIGH pulse width
t
CH
(abs)
t
CH
(avg),min * t
CK
(avg),min +
t
JIT
(duty),min
t
CH
(avg),max * t
CK
(avg),max +
t
JIT
(duty),max
ps
Absolute clock LOW pulse width
t
CL
(abs)
t
CL
(avg),min * t
CK
(avg),min +
t
JIT
(duty),min
t
CL
(avg), max * t
CK
(avg),max
+
t
JIT
(duty), max
ps
NOTE 35: t
HP
is the minimum of the absolute half period of the actual input clock. t
HP
is an input parameter but not
an input specification parameter. It is used in conjunction with t
QHS
to derive the DRAM output timing t
QH
.
The value to be used for tQH calculation is determined by the following equation;
t
HP
= Min ( t
CH
(abs), t
CL
(abs) ),
where,
t
CH
(abs) is the minimum of the actual instantaneous clock HIGH time;
t
CL
(abs) is the minimum of the actual instantaneous clock LOW time;
NOTE 36: t
QHS
accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual t
HP
at the
input is transferred to the output; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next
transition, both of which are independent of each other, due to data pin skew, output pattern effects
,
and
p-channel to n-channel variation of the output drivers
AS4C128M16D2A-25BCN
AS4C128M16D2A-25BIN
Confidential
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Rev.1.0 Dec 2015