Transcript slides

Panel Discussion
High Level Design and ESL: Who Cares?
Masahiro Fujita
VLSI Design and Education Center
(VDEC)
University of Tokyo
Questions from the organizer (1)
• With HL design models verification
becomes easier or harder ?
– HL models could be golden for RTL
verification
• This is, I believe, why industrial people are writing
HL models
– There are RTL specific properties to be
verified, such as clock crossing issues
Questions from the organizer (2)
• Starting with HL is good in general ?
– Good for more application specific ones, such as SoC
– Good for the designs where high level synthesis tools
work pretty well, such as DSP type computation
• This is, I believe, why industrial people are writing HL models
– May not be good for microprocessor designs where
performance are critical, and designs themselves are
very similar to one another
• How about BlueSpec ? It may be useful
Questions from the organizer (3)
• Rationale to start with HL (cost effective ?)
– Industrial designers (architects) like to have golden
model in the beginning to make sure the overall
behaviors
• Then, how can we use it ?
– Also they like to explore more design space with HL
models
• Need reasonably good high/system-level synthesis tools
– For HW/SW co-design, yes
• Discuss in the next slides
• Equivalence checking may not be so powerful
– For speed up of scientific computing, must be
• Discuss in the following
High level design flow and verification
(Ideal case for HW/SW co-design)
• Tools have been actually developed under Japanese Space Agency
(JAXA)
– JAXA, Toshiba, NEC, Fujitsu, UCI (Prof. Gajski) and U. of Tokyo
Design
optimization
Algorithmic design
description
Many steps of
manual refinement
Static/
Model
checking
Design
optimization
High level synthesizable
description
High level
synthesis
Design
optimization
Many steps of
manual refinement
Register Transfer Level
description
Really used for space satellite designs in Japan
Sequential
Equivalence
Checking
My conclusions
• If you can have correct RTL by itself, you do not
need HL models
– Designing something very similar to previous ones
• If you need to develop something very new,
starting with RTL designs is very difficutl
– Need to explore design space in architectural designs,
which need HL models anyway
– Need to establish functionally correct HL models as
golden for RTL designs
• If you are working under HW/SW co-designs,
anyway we have HL models
– Need good and consistent supports in system-level