第三部分 PLI 程序

PLI提供两种类型的程序：Access程序；任务和函数程序。Access 程序是能访问verilog内部的信息的C编程语言……

PLI提供两种类型的程序，他们是

access程序任务和函数程序

PLI2.0把access程序和tf程序整合为VPI函数，也澄清了PLI中的一些confusion。

Access 程序Access 程序是能访问verilog内部的信息的C编程语言。access程序能执行两个操作：

读取操作： 直接从内部数据结构中读取特定对象的数据。access程序可以读取以下对象的信息：

  例化模块  模块端口  模块通路  内部模块通路   顶层模块  例化primitive  Primitive terminals  线网  寄存器  参数  时序检查  named events  整型，实数和时间变量

写操作：向内部数据结构写入有关对象的新信息。

  模块内部通路  模块通路  例化primitives  时序检验  寄存器逻辑值  sequential UDP逻辑值

根据access的操作，可以分为六类：

   Fetch: 返回设计层次中不同对象信息   Handle: 返回设计层次中的句柄   Modify: 修改设计层次中各种对象的值   Next:   当在循环结构时，next程序寻找每个符合给定类型的对象   Utility: 执行许多操作，比如初始化和配置access程序环境   VCL：　VCL允许PLI 应用程序监测选定对象的值的改变

Access 函数参考

Routine

Description

acc_handle_scope()

This function returns the handle to the scope of an object. The scope can be either a module, task, function, named parallel block, or named sequential block.

acc_handle_by_name()

This routine returns the handle to a Verilog-HDL object based on the specified name and scope.

acc_handle_parent()

This function returns handle for the parent primitive instance or module instance of an object

acc_handle_port()

This function returns handle for a module port

acc_handle_hiconn()

This function returns the hierarchically higher net connection to a scalar module port or a bit of a vector port

acc_handle_loconn()

This function returns the hierarchically lower net connection to a scalar module port or a bit of a vector port.

acc_handle_path()

This function returns a handle to an inter-module path that represents the connection from an output port to an input port

acc_handle_modpath()

This function returns handle to the path of a module

acc_handle_datapath()

This function returns a handle to a datapath for a module instance for the specified edge-sensitive module path

acc_handle_pathin()

This function returns handle for the first net connected to a module path source

acc_handle_pathout()

This function returns handle for the first net connected to a module path destination

acc_handle_condition()

This function returns a handle to the conditional expression for the specified path

acc_handle_tchk()

This function returns handle for the specified timing check of a module (or cell)

acc_handle_tchkarg1()

This function returns handle for the net connected to the first argument of a timing check

acc_handle_tchkarg2()

This function returns handle for the net connected to the second argument of a timing check

acc_handle_simulated_net()

This function returns the simulated net associated with the collapsed net passed as an argument

acc_handle_terminal()

This function returns handle for a primitive_terminal

acc_handle_conn()

This function returns handle to the net connected to a primitive terminal

acc_handle_tfarg()

This function returns handle for the specified argument of the system task or function associated (through the PLI mechanism) with your C-language routine`

acc_fetch_attribute()

This function returns the value of a parameter or specparam named as an attribute in your source description

acc_fetch_paramtype()

This function returns the data type of a parameter as one of three predefined integer constants.

acc_fetch_paramval()

This function returns the value of a parameter or specparam

acc_fetch_defname()

This function returns a pointer to the defining name of a module instance or primitive instance

acc_fetch_fullname()

This function returns a pointer to the full hierarchical name of any named object or module path

acc_fetch_name()

This function returns a pointer to the instance name of any named object or module path

acc_fetch_delays()

This function fetches different delay values for different objects

acc_fetch_size()

This function returns the bit size of a net, register, or port.

acc_fetch_range()

This function retrieves the most significant bit and least significant bit range values for a vector.

acc_fetch_tfarg()

This function returns value of the specified argument of the system task or function associated (through the PLI mechanism) with your C-language routine

acc_fetch_direction()

This function returns the direction of a port or terminal as one of three predefined integer constants.

acc_fetch_index()

This function returns a zero-based integer index for a port or terminal

acc_fetch_edge()

This function returns the edge specifier (type) of a path input or output terminal as one of these predefined integer constants.

acc_set_value()

This function returns a pointer to a character string indicating the logic or strength value of a net, register or variable.

acc_initialize()

This function initializes the environment for access routines

acc_close()

This function frees internal memory used by access routines; resets all configuration parameters to default values

acc_configure()

This function sets parameters that control the operation of various access routines

acc_product_version()

This function returns a pointer to a character string that indicates what version of a Verilog simulator is linked to the access routines

acc_version()

This function returns a pointer to a character string that indicates version number of your access routine software

acc_count()

This function returns an integer count of the number of objects related to a particular reference object

acc_collect()

This function returns a pointer to an array that contains handles for all objects related to a particular reference object

acc_free()

This function frees memory allocated by acc_collect

acc_compare_handles()

This function returns true if the two input handles refer to the same object

acc_object_in_typelist()

This function determines whether an object fits a type or fulltype or exhibits a property specified in an input array

acc_object_of_type()

This function determines whether an object fits a specified type or fulltype, or exhibits a specified property

acc_next_cell()

This function returns the next cell instance within the region that includes the entire hierarchy below a module

acc_next_child()

This function returns the next child of a module

acc_next_modpath()

This function returns the next path of a module

acc_next_net()

This function returns the next net of a module

acc_next_parameter()

This function returns the next parameter within a module

acc_next_port()

This function returns the next input, output or inout port of a module in the order specified by the port list

acc_next_portout()

This function returns the next output or inout port of a module in the order specified by the port list

acc_next_primitive()

This function returns the next gate, switch or user-defined primitive (UDP) within a module

acc_next_specparam()

This function returns the next specparam within a module

acc_next_tchk()

This function returns the next timing check within a module

acc_next_terminal()

This function returns the next terminal of a gate, switch or user-defined primitive (UDP)

acc_next()

This function within a scope, returns the next object of each type specified in object_type_array

acc_next_topmod()

This function returns the next top-level module

acc_next_cell_load()

This function returns the next load on a net inside a cell

acc_next_load()

This function returns the next primitive terminal driven by a net

acc_next_driver()

This function returns the next primitive terminal that drives a net

acc_next_hiconn()

This function returns the next hierarchically higher net connection to a port of a module

acc_next_loconn()

This function returns the next hierarchically lower net connection to a port of a module

acc_next_bit()

This function returns the handles of each bit in an expanded vector port or expanded vector net

acc_next_input()

This function returns a handle to the next input path terminal of the specified module path or datapath

acc_next_output()

This function returns a handle to the next output path terminal of the specified module path or datapath

 

 

 

 

使用access程序流程就像在前面例子里看见的一样，在我们写用户应用程序的之前，要执行一系列步骤，如下：

1

#include <acc_user.h>

2

 

3

void pli_func() {

4

 

acc_initialize();

5

 

// Main body: Insert the user application code here

6

 

acc_close();

7

}

acc_user.h: 所有有关access程序的数据结构acc_initialize(): 初始化变量和建立环境主体： 用户定义应用acc-close()： 取消acc-initialize执行的操作

对象的句柄句柄是预定义的数据类型，类似于C中的指针，用来指向设计数据库中的对象和指向任何类型的对象。句柄是access程序的支柱，PLI1.0中引入的最重要的新概念。

申明：

handle my_handle;handle clock;handle reset;

VCL（Value change link）VCL是一个PLI应用程序来监测被选定对象值的改变

   事件   标量和矢量寄存器   标量线网   扩展的矢量线网的位选   未扩展的矢量线网

VCL不能提取有关下面对象的信息：

   Bit-selects of unexpanded vector nets or registers   部分选择   存储器   表达式