2016_MeetingNovember10 < P1076

P1076 Web>Vhdl2019MeetingMinutes>2016_MeetingNovember10 (2020-02-17, JimLewis) (raw view)EditAttach
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---+!! P1076 November 10, 2016 Meeting Minutes

---++!! Attendees:

   * Rob Gaddi, Peter Flake, Patrick Lehmann, Brent Hayhoe, Jim Lewis, Kevin Jennings,
---++!! Agenda:

<br />%TOC%

---++ Meeting Discussion
   * LCS Review
   * By December, need LCS for proposals that will go into standard.
   * December to March - prepare final document.
   * conditional compilation
      * Peter to write up LCS
      * For TOOL_NAME - require/desire short name: "GHDL" and not "GHDL Student Edition"
      * Add TOOL_EDITION s.t can enter as wish, such as "GHDL Student Edition"
      * Change VENDOR to TOOL_VENDOR
      * Add text that says vendor shall support a mechanism to pass in a user defined name and value
         * Example using DEBUG and a value.
      * TOOL_OPTIMIZATION with "LOW" "HIGH" - using low for automatic debug switches
         * Rejected at least for now can be done with user defined names
      * Change to 'end if
   * Rob
      * no update on time/date
         * Support local time and GMT
         * support for "+", "-"? No defer to future open source package
      * No update on optional ;
   * Patrick. Updates on &lt;=&gt;
      * Currently static.
      * Presented current strategy on Kobra.io - pasted later in the minutes.
   * Kevin - updated LCS's with voting section.
   * Brent - working on deferred shared variables. Will have something later.
   * Revive old style shared variables?
   * Protected types with initializer
      * See proposal for Protected types with generics [[GenericTypes]]
      * Can initialize a PT by calling a function method that returns a value (such as true) and initializes the PT by side effect.
---++ Notes about Bundles

Big picture



==============================================================
1. Spaceship
2. bundles on top of records
3. extensions
 3.1 map expression
 porta => map (sig1, sig2),
 3.2 map functions
 ...





Overall algorithm

==============================================================

1. analysis
 - parse signal declarations as usual
 - parse spaceship assignment statements as normal assignment statements would be parsed

2. elaboration
 - gather lists for "space ship connected signals" (sscs) across hierachy
 - check that:
 - all signals in a sscs must have the same subtype (not only type, so the
 resolution function is included in the definition and always the same)
 - all signals in a sscs must be either:
 - unresolved, or
 - resolved. if so, the resolution function must be the same
 - (the mixed kind might be relaxed in a future revision)
 - ...

3. runtime
3.1 runtime init
 - ...

3.2 runtime cycle
 - ...

Questions:

==============================================================

- how to handle type conversions on "slip streams" (Gene Rodenberry's Andromeda - spaceships travel on slip streams)
- so the subtype already includes the resolution function?
- can I overwrite a resolution function if I sub type a subtype with another resolution function?
- you can write sig foo : resolution_func unresolved_type; -- this creates an anonimous subtype
 - If I do it twice, are these anonymous sutypes compatible?

 

Algorithm to construct spaceship connected signals (sscs):

==============================================================

# Construction SpaceShipConnections

for block in model.statementBlocks:

if isinstance(block, ConcurrentStatementBlock):

for stmt in block.Statements:

if isinstance(stmt, SpaceShipAssignment):

t = stmt.Target

s = stmt.Source

if t.SpaceShipConnections is None:

if s.SpaceShipConnections is None: # create a new SSC

ssc = SpaceShipConnection(t, s)

s.SpaceShipConnections = ssc

else: # add t to s' SSC

ssc = s.SpaceShipConnections

ssc += t

t.SpaceShipConnections = ssc

else:

ssc = t.SpaceShipConnections

if s.SpaceShipConnections is None: # add s to t' SSC

ssc += s

else: # merge both SSCs

ssc += s.SpaceShipConnections

s.SpaceShipConnections = ssc

elif isinstance(stmt, SignalAssignment):

t = stmt.Target

s = stmt.Source

d = Driver(s)

t.Sources.append(d)

 



TODO for Spaceship
- Establish runtime algorithm
 - new step during signal resolution?
 - Applied to the smallest resolved sub-structure of a composite?
- Determine impacted LRM sections
 - Chapter 14 ...
 - 14.7.3.4 Signal update ?
 - ??
 - 14.7.5.3 Simulation cycle
 - section C & D may be impacted
- Determine full scope
 - interaction with 'unresolved signals'?
 - interaction with 'resolved signals'?
 - possible connection scenarios
 - unresolved <=> unresolved
 - resolved <=> resolved
 - unresolved <=> resolved?
 - resolved <=> resolved with different resolution functions?
 - support for 'conversion function' or 'type conversion'?


---++ Review and Approve Meeting Minutes and Decisions by Attendees

Rob, Peter, All

---++ Review and Approve Meeting Minutes and Decisions by non-attendees

&lt;Add your name below. Indicate if you agree or disagree&gt;

&lt;If you disagree, add a list of items you disagree with and initiate a reflector discussion&gt;

TBD

---++ Next Meeting: Thursday [[2016_MeetingNovember17][November 17, 2016]], 11 am Pacific
---+++ Previous Meeting: Thursday [[2016_MeetingNovember3][November 3, 2016]]
Topic revision: r4 - 2020-02-17 - 15:36:17 - JimLewis
P1076