ITEA 2 – 09033: TIMMO-2-USE Timing Model – Tools, algorithms, languages, methodology, USE cases 2012-09- 24..25 AMST Workshop - Berlin Slide 1 Modeling timing constraints, parameterized and multi-clock systems in TADL2 Johan Nordlander, Chalmers University of Technology
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Modeling timing constraints, parameterized and multi-clock systems in TADL2
Modeling timing constraints, parameterized and multi-clock systems in TADL2. Johan Nordlander, Chalmers University of Technology. System models & constraints. A system model:. cost. timing. logical. resource usage. structural. - PowerPoint PPT Presentation
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ITEA 2 – 09033: TIMMO-2-USE
Timing Model –Tools, algorithms, languages, methodology, USE cases
2012-09-24..25 AMST Workshop - Berlin Slide 1
Modeling timing constraints, parameterized and multi-clock
systems in TADL2
Johan Nordlander, Chalmers University of Technology
System models & constraints
2012-09-24..25 AMST Workshop - Berlin Slide 2
A system model:
Industry objective: specify / characterize / verify models using constraints
logical...
resource usage...
cost...timing...
structural...
TADL2 (Timing Augmented Description Language)
2012-09-24..25 AMST Workshop - Berlin Slide 3
A language of timing constraints (and timing constraints only)
TADL2
Model
ConstraintsConnecting points:the events exposedby a system model
Delay... Periodic...
Events & occurrences
2012-09-24..25 AMST Workshop - Berlin Slide 4
For each execution / simulation / prediction of a system,every event occurs a some points in time.
Model
time
TADL2 constraintsput demands on therelative placementof such occurrences
Source-to-target delay• What if source repeats?• Can multiple target
occurrences match?• Are stray target
occurrences allowed?
The need for semantic precision
2012-09-24..25 AMST Workshop - Berlin Slide 5
• But what about jitter?• What if jitter > period?• What if repetition stops?
• Is jitter meaningful here too?• Same as upper-lower difference?• Accumulating vs. non-accumulating drift?
Some well-known occurrence patterns:
Periodic repetition
Sporadic repetition
DelayConstraint
2012-09-24..25 AMST Workshop - Berlin Slide 6
DelayConstraint (source, target, lower, upper)x source : y target : lower ≤ y – x ≤ upper
time
source
target
lowerupper
duplicate and stray occurrences allowed
StrongDelayConstraint
2012-09-24..25 AMST Workshop - Berlin Slide 7
StrongDelayConstraint (source, target, lower, upper)i : x : x = source(i) y : y = target(i) : lower ≤ y – x ≤ upper
time
source
target
lowerupper
1 2 3
1 2 3
duplicate and stray occurrences disallowed(lock-step enforced)
ReactionConstraint
2012-09-24..25 AMST Workshop - Berlin Slide 8
time
minimummaximum
stimulus
response
scope
ReactionConstraint ( scope, minimum, maximum )x scope.stimulus : y scope.response :