EtronTech
EM68916CWQA
tJIT(CH) = {tCHi- tCH(avg) where i=1 to 200}
tJIT(CL) = {tCLi- tCL(avg) where i=1 to 200}
- tJIT(per), tJIT(per,lck)
tJIT(per) is defined as the largest deviation of any single tCK from tCK(avg).
tJIT(per) = Min/max of {tCKi- tCK(avg) where i=1 to 200}
tJIT(per) defines the single period jitter when the DLL is already locked.
tJIT(per,lck) uses the same definition for single period jitter, during the DLL locking period only.
tJIT(per) and tJIT(per,lck) are not guaranteed through final production testing.
- tJIT(cc), tJIT(cc,lck)
tJIT(cc) is defined as the difference in clock period between two consecutive clock cycles:
tJIT(cc) = Max of |tCKi+1 – tCKi
|
tJIT(cc) defines the cycle to cycle jitter when the DLL is already locked.
tJIT(cc,lck) uses the same definition for cycle to cycle jitter, during the DLL locking period only.
tJIT(cc) and tJIT(cc,lck) are not guaranteed through final production testing.
- tERR(2per), tERR (3per), tERR (4per), tERR (5per), tERR (6-10per) and tERR (11-50per)
tERR is defined as the cumulative error across multiple consecutive cycles from tCK(avg).
⎧
⎪
⎪
⎪
n=2
n=3
n=4
n=5
for
for
for
for
2per
3per
4per
5per
(
(
(
(
(
)
)
)
)
tERR
tERR
tERR
tERR
tERR
tERR
i +N−1
⎡
⎤
⎥
⎦
⎪
⎨
nper =
− N ×
(
avg
CK
where
(
)
(
)
)
⎢ ∑
tERR
t
t
CKj
j=1
⎣
⎪
⎪
⎪
⎪
6 ≤ n ≤ 10 for
6 −10per
)
11≤ n ≤ 50 for
11− 50per
(
)
⎩
NOTE 32: 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.)
Parameter
Symbol
Min
Max
Unit
tCK(avg),min + tJIT(per),min
tCK(avg),max + tJIT(per),max
ps
Absolute clock period
tCK (abs)
tCH(avg),min * tCK(avg),min +
tJIT(duty),min
tCL(avg),min * tCK(avg),min +
tJIT(duty),min
tCH(avg),max * tCK(avg),max + ps
tJIT(duty),max
tCL(avg), max * tCK(avg),max + ps
tJIT(duty), max
Absolute clock HIGH pulse width tCH (abs)
Absolute clock LOW pulse width tCL (abs)
NOTE 33: tHP is the minimum of the absolute half period of the actual input clock. tHP is an input parameter but
not an input specification parameter. It is used in conjunction with tQHS to derive the DRAM output timing
tQH. The value to be used for tQH calculation is determined by the following equation;
tHP = Min ( tCH(abs), tCL(abs) ),
where,
tCH(abs) is the minimum of the actual instantaneous clock HIGH time;
tCL(abs) is the minimum of the actual instantaneous clock LOW time;
NOTE 34: tQHS accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual tHP 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
Etron Confidential
32
Rev. 1.1
Apr. 2009
ETRON [ ETRON TECHNOLOGY, INC. ]
