Programming Language Interface PLI

1
Programming Language Interface (PLI)

• Pedram A. Riahi
• Test Seminar
• August 11th, 2004

2
Contents

• PLI History
• Verilog PLI Overview
• Verilog VPI Routines
• Cadence VPI Environment
• Mentor Graphics VPI Environment
• References

3
PLI History

• 1985 - The PLI was developed by Gateway Design
  Automation as part of the proprietary Verilog-XL
  simulator
• 1990 - The PLI standard was released to the
  public domain along with the Verilog HDL and
  Verilog SDF standards by Cadence Design System
• 1990 - Open Verilog International (OVI) owned
  the Verilog HDL, the OVI version of the PLI was
  called PLI 1.0
• 1993 - OVI released PLI 2.0, a completely new
  interface, intended to replace PLI 1.0
• 1993 - OVI submitted Verilog to the IEEE for
  standardization
• 1995 -The IEEE-1364-1995 Verilog PLI standard was
  released
• 2001 -The IEEE-1364-2001 Verilog HDL PLI
  standard updated with many new language features
  many new language features

4
Verilog PLI Overview

• IEEE Std Verilog HDL LRM Clauses 20-27 and
  Appendices E-G
• Verilog PLI Generations
• Task/Function Routines
• (TF Routines, tf_)
• Access Routines
• (ACC Routines, acc_)
• Verilog Procedural Interface Routines
• (VPI Routines, vpi_)

5
Verilog PLI Overview

• User-Defined System Tasks and Functions
• Names ()
• Types
• Overriding
• User-Supplied PLI Applications
• Arguments
• Interface Mechanism
• Include Files
• acc_user.h
• veriuser.h
• vpi_user.h
• Memory Restriction

6
Verilog VPI Routines

• System Tasks and Functions
• vpi_register_systf()
• vlog_startup_routines
• Interface
• Call-backs
• vpi_register_cb()
• Access to HDL and Simulation Objects
• module m, wire w m1.w, m2.w
• Error Handling
• Function Availability
• Traversing Expressions

7
Verilog VPI Routines

• Call-backs
• Simulation Call-backs
• Simulation Action and Features
• Simulation Times
• Simulation Events
• Statement Call-backs
• Removing Call-backs
• Time Queue

8
Verilog VPI Routines

• Diagram Key for Objects and Classes
• Object Definition
• Object Reference
• Class Definition
• Class Reference
• Unnamed Class

9
Verilog VPI Routines

• Diagram Key for Traversing Relationships
• obj_h vpi_handle (obj, ref_h)
• obj_h vpi_handle (Tag, ref_h)
• obj_h vpi_handle (obj, NULL)

10
Verilog VPI Routines

• Diagram Key for Traversing Relationships
• itr vpi_iterate (obj, ref_h)
• while (obj_h vpi_scan (itr))
• process obj_h
• itr vpi_iterate (Tag, ref_h)
• while (obj_h vpi_scan (itr))
• process obj_h
• itr vpi_iterate (obj, NULL)
• while (obj_h vpi_scan (itr))
• process obj_h

11
Verilog VPI Routines

• Diagram Key for Accessing Properties
• PLI_INT32 vect_flag
• vpi_get (vpiVector, obj_h)
• PLI_INT32 size
• vpi_get (vpiSize, obj_h)
• PLI_INT8 name
• vpi_get_str (vpiName, obj_h)
• Identified Routines

12
Verilog VPI Routines

• Object Relationships and Properties
• modH vpi_handle (vpiModule, netH)

13
Verilog VPI Routines

• Object Relationships and Properties
• vpiHandle net, mod
• net vpiHandle_by_name (top.m1.w, NULL)
• mod vpi_handle (vpiModule, net)
• vpi_handle (vpiExpr, partH)

14
Verilog VPI Routines

• Object Relationships and Properties
• PLI_BYTE8 name
• vpi_get_str (vpiFullName, mod)
• vpiHandle itr
• itr vpi_iterate(vpiNet, mod)
• while (net vpi_scan (itr))
• vpi_printf(s\n,
• vpi_get_str (vpiFullName, net))

15
Verilog VPI Routines

• Object Relationships and Properties
• void traverseExpr (vpiHandle expr)
• vpiHandle subExprI, subExprH
• switch (vpi_get (vpiExpr, expr))
• case vpiOperation
• subExprI vpi_iterate (vpiOperand,
• expr)
• if (subExprI)
• while (subExprH
• vpi_scan (subExprI))
• traverseExpr (subExprH)
• default break

16
Verilog VPI Routines

• Object Relationships and Properties
• Type Properties
• -gt type
• int vpiType
• vpi_get (vpiType, H)
• vpi_get_str (vpiType, H)
• File and Line Properties
• -gt location
• int vpiLineNo
• str vpiFile
• Delays and Values

17
Verilog VPI Routines

• VPI Routines for Simulation Related Call-backs
• vpi_register_cb()
• Register a simulation-related call-back
• vpi_remove_cb()
• Remove a simulation-related call-back
• vpi_get_cb_info()
• Get information about a simulation-related
  call-back

18
Verilog VPI Routines

• VPI Routines for System Task/Function Call-backs
• vpi_register_systf()
• Register a system task/function call-back
• vpi_get_systf_info()
• Get information about a system task/function
  call-back

19
Verilog VPI Routines

• VPI Routines for Traversing Verilog HDL Hierarchy
• vpi_handle()
• Obtain a handle for an object with a one-to-one
  relationship
• vpi_iterate(), vpi_scan()
• Obtain handles for objects in a one-to-many
  relationship
• vpi_handle_multi()
• Obtain a handle for an object in a many-to-one
  relationship

20
Verilog VPI Routines

• VPI Routines for Accessing Properties of Objects
• vpi_get()
• Get the value of objects with types of int or
  bool
• vpi_get_str()
• Get the value of objects with types of string

21
Verilog VPI Routines

• VPI Routines for Accessing Objects from
  Properties
• vpi_handle_by_name()
• Obtain a handle for a named object
• vpi_handle_by_index()
• Obtain a handle for an indexed object
• vpi_handle_by_multi_index()
• Obtain a handle to a word or bit in an array

22
Verilog VPI Routines

• VPI Routines for Delay Processing
• vpi_get_delays()
• Retrieve delays or timing limits of an object
• vpi_put_delays()
• Write delays or timing limits to an object

23
Verilog VPI Routines

• VPI Routines for Logic and Strength Value
  Processing
• vpi_get_value()
• Retrieve logic value or strength value of an
  object
• vpi_put_value()
• Write logic value or strength value to an object

24
Verilog VPI Routines

• VPI Routines for Simulation Time Processing
• vpi_get_time()
• Find the current simulation time or the
  scheduled time of future events

25
Verilog VPI Routines

• VPI Routines for Miscellaneous Utilities
• vpi_printf()
• vpi_vprintf()
• vpi_flush()
• vpi_mcd_open()
• vpi_mcd_close()
• vpi_mcd_printf()
• vpi_mcd_vprintf()
• vpi_mcd_flush()
• vpi_mcd_name()
• vpi_get_vlog_info()
• vpi_compare_objects()
• vpi_chk_error()
• vpi_free_object()
• vpi_put_data()
• vpi_get_data()
• vpi_put_userdata()
• vpi_get_userdata()
• vpi_sim_control()

26
Verilog VPI Routines

• Module Data Model

27
Verilog VPI Routines

• Net Data Model

28
Verilog VPI Routines

• Reg Data Model

29
Verilog VPI Routines

• Cadence PLI Environment

30
Verilog VPI Routines

• Cadence PLI Environment
• Creating a C Function
• include ltstdio.hgt
• include vpi_user.h
• int hello_task ()
• vpi_printf (Hello from a new VPI task \n)
• Creating a C Function
• extern C void ncmain (int, char )
• main(argc, argv)
• int argc
• char argv
• ncmain(argc, argv)

31
Verilog VPI Routines

• Cadence PLI Environment
• Associating C Function with a new System Task
• void register_my_systfs ()
• s_vpi_systf_data task_data_s
• p_vpi_systf_data task_data_p task_data_s
• task_data_p-gttype vpiSysTask
• task_data_p-gttfname hello
• task_data_p-gtcalltf (int()()) hello_task
• task_data_p-gtcompiletf NULL
• vpi_register_systf (task_data_p)

32
Verilog VPI Routines

• Cadence PLI Environment
• Registering Users New System Task
• / vpi_user.c /
• include vpi_user.h
• include vpi_user_cds.h
• void (vlog_startup_routines) ()
• register_my_systfs, 0
• Invoking Users System Task
• module top
• Initial begin hello end
• endmodule

33
Verilog VPI Routines

• Cadence PLI Environment
• Compiling C Files (vconfig)
• Static/Dynamic
• cc -KPIC -c /vpi_user.c -IltInstDirgt/include
• cc -KPIC -c /hello.c -IltInstDirgt/include
• ld -G vpi_user.o hello.o -o libvpi.so
• executable file
• Compiling and Simulating Verilog File
• setenv LD_LIBRARY_PATH \ /ltLibDirgtLD_LIBRARY_PA
  TH
• ncelab accessrwc worklib.topv
• ncverilog ncaccessrwc plinowarn hello.v

34
Verilog VPI Routines

• Mentor Graphics PLI Environment
• Compiling C Files
• cc -c /vpi_user.c -IltInstDirgt/include
• cc -c /hello.c -IltInstDirgt/include
• ld -G vpi_user.o hello.o -o vpi_lib.so
• Compiling and Simulating Verilog File
  (modelsim.ini)
• vlib work
• vlog hello.v
• vsim -c -pli vpi_lib.so top

35
References

• Cadence Design Systems, Inc., VPI User Guide and
  Reference, Product Version 3.2, Dec. 2000.
• Cadence Design Systems, Inc., NC-Verilog
  Simulator Help, Product Version 3.2, Dec. 2000.
• Cadence Design Systems, Inc., Verilog-XL User
  Guide and Reference, Product Version 2.8, Aug.
  1999.
• Mentor Graphics, ModelSim SE User's Manual,
  Version 5.7a, Jan. 2003
• Stuart Sutherland, The Verilog PLI Handbook,
  Kluwer Academic Publishers, 2002.
• Swapnajit Mittra, Principles of Verilog PLI,
  Kluwer Academic Publishers, 1999.