VHDL Study Group Meeting 3/3/2011 8 am Attendees: David Bishop - Kodak Martin Thompson - TRW Automotive Jerry Kaczynski - Aldec Chuck Swart - Mentor John Shields - Mentor Peter Flake Jim Lewis - SynthWorks Ryan Hinton - L3 Com Discussion: Review IEEE patent policy (please read before meeting): https://development.standards.ieee.org/myproject/Public/mytools/mob/slideset.pdf Approve Feb 17 meeting minutes: Motion John 2nd Martin Continue discussion of language change requirements. John Shields Goal: SV testbench to VHDL TB integration & VHDL testbench VHDL-DPI In and Out parms marshalled into interface defined manner Program short step from C to VHDL - no information model ala VHPI From a C program call VHDL in a similar manner DPI classes to records or other VHDL structure w/ VHPI much more work to walk the information model Peter Flake DPI pass around an anonymous pointer Implicit port association by name SV .* operator Helps do system verilog assertion binds SV protocol checkers are part of a separate model Bind SV assertion model More explination on reflector David Bishop: likes it - but personally would not use it Martin: since tools do it, why have the language do it not very VHDL like Ryan Hinton: likes it, but most of the time not use C++ FAQ - clear distiction btw legal and moral in a programming language Use: Subprogram with lots of arguments Entity with lots of arguments most of the time explicit Jim: Like martin not very vhdl like Like Ryan: need something to make some cases easier, but VHDL-2008 introduces syntax for generics with defaults, perhaps that would be good Garbage collection - automatic memory management Better integrate with memory management model of SV Deallocate Rather than deallocate, make pointer null and garbage collection does the rest. Ryan: Other languages do this. Not trivial, but not new Peter: Compatibility issues Backward compatible deallocate and performance Martin: allow if type explicitly allows it. Ryan: Smart pointers - C++ explicit allocation/deallocation Libraries with smart pointers that do automatic Ryan: Flatten function - transformations between array and matricies implicit language operator David: also has similar issues David: When strong typing goes bad How weaken up - Jim: anonymous array of std_logic ; Ryan: pass around original data type - where knew type Peter: Blue spec - strong typing - with specification of mapping to bits David: Matrix packages 1076.1 - Real Matrix - in real (signed, unsigned, ufixed, sfixed) Ryan: Matrix type fixed at 2 dimensions David: hard to do further dimensions: Matrix 3, Ryan: Some languages specify flat array and dimensions of the arrays. Makes reshape operations trivial. Ryan: VHDL library of dynamic memory types - linked lists - queues - stacks dynamically sized vector - associative array/dictionary - sets C++ standard template library / Boost / Jquery / python libs Jim: Issues use protected types object as an input to a function Language does not allow Next Meeting: Thursday March 17 at 8 am