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SEMI G80-0200 © SE MI 2000 24 Drive to Com p are Edge Error -50 pS +50pS Compar e Error MI N Value- MI N is the value all comparato rs are programme d to when the first drive edg e is detected . For a sw eep- Compare edg…
SEMI G80-0200 © SEMI 200023
possible in Level 1. All that is known per Level 1
analysis is that the positive error is 350ps and the
negative error is 250ps.
A2-1.4 Positive and Negative Error — EQUATION 1:
Per the examples in this Appendix and data taken out of
Table 1:
Positive Error = Reference - Max Value
Negative Error = Reference - Min Value
SEMI G80-0200 © SEMI 2000 24
Drive to Compare Edge Error
-50pS +50pS
Compare Error
MIN Value- MIN is the value all
comparators are programmed to when
the first drive edge is detected.
For a sweep- Compare edges
should be programmed far in
advance of the reference signal
allowing enough room to detect
the earliest occurrence of a drive
edge.
TIMING RELATIONSHIPS, DEFINITIONS & EXAMPLE RESULTS
DEFINITIONS-
Reference- The programmed value of the drivers
Drive to Compare Error- The difference between the median value for Drive and the median value for Compare error.
RELATIONSHIPS & EXAMPLE RESULTS-
Negative Error: Min Value - Reference = 900pS - 1000pS = -100pS
Positive Error: Max Value - Reference = 1200pS - 1000pS = 200pS
Drive to Compare Error: Reference - [(Min Value + Max Value)/2] = 1000ps - [(900ps + 1200pS)/2] = -50pS
For a sweep- Compare edges
should be programmed far beyond
the reference signal allowing
enough room to detect the latest
occurrence of a drive edge.
Detect MAX drive value- Detect
the latest occurrence of the drive
edge with the earliest compare
ed
g
e
(
last fail
)
Detect MIN drive value- Detect the
earliest occurrence of the drive
edge with the latest compare edge
(
first
p
ass
)
-100pS
Drive Edges
1000pS Drive
Reference
+100pS
50pS
-100pS +100pS
Drive Error
Drive
Reference
Drive Edges
-100pS
1000pS Drive
Reference
+100pS
In this example:
Drive edge error = ± 100pS
Compare edge error = ± 50pS
Drive to Compare error = - 50pS
This example will illustrate how
numerical error values are obtained.
MAX Value- MAX is the value all
comparators are programmed to when
the last drive edge is detected.
1200pS
(Max value)
Sweep
Compare Edges
900pS
(Min value)
Sweep
Compare Edges
N
OTE: All drive edges are
detected in parallel in pairs:
pin 1 & 2, 3 & 4,...n-1 & n.
N
OTE: All drive edges are
detected in parallel in pairs:
pin 1 & 2, 3 & 4,...n-1 & n.
1200pS
1000pS Reference
-100pS +100pS
50pS
Drive
Reference
Last Fail
Max Value
When the edges on all pins are
detected the drive to compare erro
r
relationship will appear as
indicated here with associated erro
r
values indicated.
-50
p
S
+50pS
-50pS +50pS
1
000pS
Last fail
First pass
950pS
+50pS-50pS
900pS
1200pS
0nS
0nS
900pS
First Pass
Min Value
Figure A2-1
Level 1 Compare Edge Error << Drive Edge
SEMI G80-0200 © SEMI 200025
Drive to Compare Edge Error
Compare Error
MIN Value- MIN is the value
all comparators are
programmed to when the first
drive edge is detected.
For a sweep- Compare edges
should be programmed far in
advance of the reference signal
allowing enough room to detect
the earliest occurrence of a drive
edge.
TIMING RELATIONSHIPS, DEFINITIONS & EXAMPLE RESULTS
DEFINITIONS-
Reference- The programmed value of the drivers
Drive to Compare Error- The difference between the average of min & max for Drive and the
average of min & max for Compare error.
RELATIONSHIPS & EXAMPLE RESULTS-
Negative Error: Reference - Min Value = 1000ps - 900ps = 100ps
Positive Error: Reference - Max Value = 1000ps - 1200ps = -200ps
Drive to Compare Error: Reference - [(Min Value + Max Value)/2] = 1000ps - [(900ps + 1200ps )/2] = -50ps
For a sweep- Compare edges
should be programmed far
beyond the reference signal
allowing enough room to detect
the latest occurrence of a drive
edge.
MAX drive value- Detect the
latest occurrence of the drive
edge with the earliest compare
edge (last fail- Timing Linearity
test 10.3.1)
MIN drive value- Detect the
earliest occurrence of the drive
edge with the latest compare edge
(first pass- Timing Linearity Test
10.3.1)
50ps
In this example:
Drive edge error = ±50ps
Compare edge error = ±100ps
Drive to Compare error = - 50ps
This example will illustrate how
numerical error values are obtained.
MAX value- MAX is the value
all comparators are programmed
to when the last drive edge is
detected.
1200ps
(Max Value)
NOTE: All drive edges are
detected in parallel in pairs: pin 1
& 2, 3 & 4,...n-1 & n.
NOTE: All drive edges are detected in
parallel in pairs: pin 1 & 2, 3 & 4,...n-1
& n.
900ps
950ps
1000ps Reference
50ps
First Pass
Min value
Last Fail
Max value
When the edges on all pins are
detected the drive to compare
error relationship will appear as
indicated here with associate
d
error values indicated.
-100ps
-100ps +100ps
900ps
(Min value)
Sweep
Compare Edges
-100ps +100ps
1000ps Drive
Reference
1000ps
Last fail
Sweep
+100ps-100ps
First pass
50ps
-50ps +50psDrive Error
Drive
Reference
-50ps +50psDrive Edges
-50ps +50psDrive Edges
1000ps Drive
Reference
-50ps +50ps
Drive
Reference
+100ps
0
n
s
1200ps
0
n
s
900ps
1200ps
Compare Edges
Figure A2-2
Level 1 Drive Edge Error << Compare Edge Error