2011年5月28日 星期六
blocking vs nonblocking
從UVM user guide抽出的文句整理
blocking—
1. the tasks block execution until they complete;
2. they are not allowed to fail.
3. There is no mechanism for any blocking call to terminate abnormally or
otherwise alter the flow of control.
4, They simply wait until the request is satisfied.
5. In a timed system, this means that time may pass between the time the call was initiated and the time it returns.
nonblocking
1. call returns immediately.
2. call guarantee that the call returns in the same delta cycle in which it was issued, that is, without consuming any time, not even a single delta cycle.
3. In UVM, nonblocking calls are modeled as functions.
blocking—
1. the tasks block execution until they complete;
2. they are not allowed to fail.
3. There is no mechanism for any blocking call to terminate abnormally or
otherwise alter the flow of control.
4, They simply wait until the request is satisfied.
5. In a timed system, this means that time may pass between the time the call was initiated and the time it returns.
nonblocking
1. call returns immediately.
2. call guarantee that the call returns in the same delta cycle in which it was issued, that is, without consuming any time, not even a single delta cycle.
3. In UVM, nonblocking calls are modeled as functions.
uvm_tlm_fifo使用blocking的另一個例子
這是從http://testbench.in/UT_14_UVM_TLM_2.html
的uvm_tlm_4.tar
的例子
`include "uvm.svh"
import uvm_pkg::*;
`include "consumer.sv"
`include "producer.sv"
class env extends uvm_env;
producer p;
consumer c;
uvm_tlm_fifo #(int) f;
function new(string name = "env");
super.new(name);
p = new("producer", this);
c = new("consumer", this);
f = new("fifo", this);
endfunction
function void connect();
p.put_port.connect(f.put_export);
c.get_port.connect(f.get_export);
endfunction
task run();
#1000 global_stop_request();
endtask
endclass
module test;
env e;
initial begin
e = new();
run_test();
end
endmodule
class producer extends uvm_component;
uvm_blocking_put_port#(int) put_port;
function new(string name, uvm_component p = null);
super.new(name,p);
put_port = new("put_port", this);
endfunction
task run;
int randval;
for(int i = 0; i < 10; i++)
begin
#10;
randval = $urandom_range(11,100);
`uvm_info("producer", $sformatf("sending %d",randval), UVM_MEDIUM)
put_port.put(randval);
end
endtask
endclass : producer
class consumer extends uvm_component;
uvm_blocking_get_port#(int) get_port;
function new(string name, uvm_component p = null);
super.new(name,p);
get_port = new("get_port", this);
endfunction
task run;
int val;
forever
begin
get_port.get(val);
`uvm_info("consumer", $sformatf("receiving %d", val), UVM_MEDIUM)
end
endtask
endclass : consumer
的uvm_tlm_4.tar
的例子
`include "uvm.svh"
import uvm_pkg::*;
`include "consumer.sv"
`include "producer.sv"
class env extends uvm_env;
producer p;
consumer c;
uvm_tlm_fifo #(int) f;
function new(string name = "env");
super.new(name);
p = new("producer", this);
c = new("consumer", this);
f = new("fifo", this);
endfunction
function void connect();
p.put_port.connect(f.put_export);
c.get_port.connect(f.get_export);
endfunction
task run();
#1000 global_stop_request();
endtask
endclass
module test;
env e;
initial begin
e = new();
run_test();
end
endmodule
class producer extends uvm_component;
uvm_blocking_put_port#(int) put_port;
function new(string name, uvm_component p = null);
super.new(name,p);
put_port = new("put_port", this);
endfunction
task run;
int randval;
for(int i = 0; i < 10; i++)
begin
#10;
randval = $urandom_range(11,100);
`uvm_info("producer", $sformatf("sending %d",randval), UVM_MEDIUM)
put_port.put(randval);
end
endtask
endclass : producer
class consumer extends uvm_component;
uvm_blocking_get_port#(int) get_port;
function new(string name, uvm_component p = null);
super.new(name,p);
get_port = new("get_port", this);
endfunction
task run;
int val;
forever
begin
get_port.get(val);
`uvm_info("consumer", $sformatf("receiving %d", val), UVM_MEDIUM)
end
endtask
endclass : consumer
2011年5月27日 星期五
改成blocking mode 的uvm_tlm_fifo
這個例子是從UVM example中挖出來的
原例是用non-blocking來實作的
此例把它改成blocking 的實作方法
module test;
import uvm_pkg::*;
class packet;
int i;
function new(int v); i=v; endfunction
endclass
class producer extends uvm_component;
uvm_blocking_put_port #(packet) data_out;
function new(string name, uvm_component parent);
super.new(name,parent);
data_out = new("data_out", this);
endfunction
task run();
packet p, pp;
#1 p=new(0);
//不用try_put了，直接put就好了，因為是blocking
//while(data_out.try_put(p)) begin
for (int i=0;i<10;i++) begin
#10 p = new(p.i);
$display("%0t: put data %0d", $time, p.i);
data_out.put(p);
end
//$display("try_put status return: %0d", p.i);
//$display("%0t: waiting to do a valid blocking put = %d", $time, p.i);
data_out.put(p);
$display("%0t: last blocking put = %d", $time, p.i);
endtask
endclass
class consumer extends uvm_component;
uvm_blocking_get_port #(packet) data_in;
function new(string name, uvm_component parent);
super.new(name,parent);
data_in = new("data_in", this);
endfunction
task run();
packet p;
/*
#100; // fifo will fill up
$display("%0t: getting one", $time);
data_in.get(p);
$display("%0t: valid recieved data %0d", $time, p.i);
#100; // let the blocking put succeed
*/
//因為blocking所以直接等待就可以了
forever begin
data_in.get(p);
$display("%0t: recieved data %0d", $time, p.i);
#10;
end
//$display ("%0t:; wait next data", $time);
/*
#100;
//data_in.get(p);
$display("%0t: got last recieved data %0d", $time, p.i);
*/
endtask
endclass
producer prod = new("prod", null);
consumer cons = new("cons", null);
uvm_tlm_fifo #(packet) fifo = new("fifo", null, 10);
initial begin
prod.data_out.connect(fifo.put_export);
cons.data_in.connect(fifo.get_export);
fork
run_test();
repeat(30) begin
$display("%0t: Show TOP FIFO level %0d of %0d", $time, fifo.used(), fifo.size());
#10;
end
#5us global_stop_request();
join
end
endmodule
原例是用non-blocking來實作的
此例把它改成blocking 的實作方法
module test;
import uvm_pkg::*;
class packet;
int i;
function new(int v); i=v; endfunction
endclass
class producer extends uvm_component;
uvm_blocking_put_port #(packet) data_out;
function new(string name, uvm_component parent);
super.new(name,parent);
data_out = new("data_out", this);
endfunction
task run();
packet p, pp;
#1 p=new(0);
//不用try_put了，直接put就好了，因為是blocking
//while(data_out.try_put(p)) begin
for (int i=0;i<10;i++) begin
#10 p = new(p.i);
$display("%0t: put data %0d", $time, p.i);
data_out.put(p);
end
//$display("try_put status return: %0d", p.i);
//$display("%0t: waiting to do a valid blocking put = %d", $time, p.i);
data_out.put(p);
$display("%0t: last blocking put = %d", $time, p.i);
endtask
endclass
class consumer extends uvm_component;
uvm_blocking_get_port #(packet) data_in;
function new(string name, uvm_component parent);
super.new(name,parent);
data_in = new("data_in", this);
endfunction
task run();
packet p;
/*
#100; // fifo will fill up
$display("%0t: getting one", $time);
data_in.get(p);
$display("%0t: valid recieved data %0d", $time, p.i);
#100; // let the blocking put succeed
*/
//因為blocking所以直接等待就可以了
forever begin
data_in.get(p);
$display("%0t: recieved data %0d", $time, p.i);
#10;
end
//$display ("%0t:; wait next data", $time);
/*
#100;
//data_in.get(p);
$display("%0t: got last recieved data %0d", $time, p.i);
*/
endtask
endclass
producer prod = new("prod", null);
consumer cons = new("cons", null);
uvm_tlm_fifo #(packet) fifo = new("fifo", null, 10);
initial begin
prod.data_out.connect(fifo.put_export);
cons.data_in.connect(fifo.get_export);
fork
run_test();
repeat(30) begin
$display("%0t: Show TOP FIFO level %0d of %0d", $time, fifo.used(), fifo.size());
#10;
end
#5us global_stop_request();
join
end
endmodule
轉移OVM VIP到UVM
如果我要將用OVM寫的testbench
改成用UVM
最好的方法是用手動更改
這樣會比較好debug
找出那裏改錯了
基本上將
OVM --> UVM
ovm --> uvm
`message -> `uvm_info
此處語法可參考下面
`uvm_info(get_type_name(), $psprintf("Transfer collected :\n%s",
trans_collected.sprint()), UVM_FULL)
就可以了
目前我的case這樣就可以動了
其他還沒遇到
如果不採用手動
有一個寫好的perl
放在
http://bbs.eetop.cn/viewthread.php?tid=282024
請自行下載
在我自己的case上
遇到不少問題
改成用UVM
最好的方法是用手動更改
這樣會比較好debug
找出那裏改錯了
基本上將
OVM --> UVM
ovm --> uvm
`message -> `uvm_info
此處語法可參考下面
`uvm_info(get_type_name(), $psprintf("Transfer collected :\n%s",
trans_collected.sprint()), UVM_FULL)
就可以了
目前我的case這樣就可以動了
其他還沒遇到
如果不採用手動
有一個寫好的perl
放在
http://bbs.eetop.cn/viewthread.php?tid=282024
請自行下載
在我自己的case上
遇到不少問題
uvm_tlm_fifo在uvm library中的範例
這個例子是從UVM example中挖出來的
此例是用non-blocking來實作的
原來的example上的說明有誤
我將它作了一些修改
module test;
import uvm_pkg::*;
class packet;
int i;
function new(int v); i=v; endfunction
endclass
class producer extends uvm_component;
uvm_put_port #(packet) data_out;
function new(string name, uvm_component parent);
super.new(name,parent);
data_out = new("data_out", this);
endfunction
task run();
packet p, pp;
#1 p=new(0);
while(data_out.try_put(p)) begin
$display("%0t: try put data %0d", $time, p.i);
#10 p = new(p.i+1);
end
$display("try_put status return: %0d", p.i);
$display("%0t: waiting to do a valid non-blocking put = %d", $time, p.i);
data_out.put(p);
$display("%0t: last non-blocking put = %d success", $time, p.i);
endtask
endclass
class consumer extends uvm_component;
uvm_get_port #(packet) data_in;
function new(string name, uvm_component parent);
super.new(name,parent);
data_in = new("data_in", this);
endfunction
task run();
packet p;
#100; // fifo will fill up
$display("%0t: getting one", $time);
data_in.get(p);
$display("%0t: valid recieved data %0d", $time, p.i);
#100; // let the blocking put succeed
while(data_in.try_get(p)) begin
$display("%0t: try recieved data %0d", $time, p.i);
#10;
end
endtask
endclass
producer prod = new("prod", null);
consumer cons = new("cons", null);
uvm_tlm_fifo #(packet) fifo = new("fifo", null, 10);
initial begin
prod.data_out.connect(fifo.put_export);
cons.data_in.connect(fifo.get_export);
fork
run_test();
repeat(30) begin
$display("%0t: Show TOP FIFO level %0d of %0d", $time, fifo.used(), fifo.size());
#10;
end
#5us global_stop_request();
join
end
endmodule
此例是用non-blocking來實作的
原來的example上的說明有誤
我將它作了一些修改
module test;
import uvm_pkg::*;
class packet;
int i;
function new(int v); i=v; endfunction
endclass
class producer extends uvm_component;
uvm_put_port #(packet) data_out;
function new(string name, uvm_component parent);
super.new(name,parent);
data_out = new("data_out", this);
endfunction
task run();
packet p, pp;
#1 p=new(0);
while(data_out.try_put(p)) begin
$display("%0t: try put data %0d", $time, p.i);
#10 p = new(p.i+1);
end
$display("try_put status return: %0d", p.i);
$display("%0t: waiting to do a valid non-blocking put = %d", $time, p.i);
data_out.put(p);
$display("%0t: last non-blocking put = %d success", $time, p.i);
endtask
endclass
class consumer extends uvm_component;
uvm_get_port #(packet) data_in;
function new(string name, uvm_component parent);
super.new(name,parent);
data_in = new("data_in", this);
endfunction
task run();
packet p;
#100; // fifo will fill up
$display("%0t: getting one", $time);
data_in.get(p);
$display("%0t: valid recieved data %0d", $time, p.i);
#100; // let the blocking put succeed
while(data_in.try_get(p)) begin
$display("%0t: try recieved data %0d", $time, p.i);
#10;
end
endtask
endclass
producer prod = new("prod", null);
consumer cons = new("cons", null);
uvm_tlm_fifo #(packet) fifo = new("fifo", null, 10);
initial begin
prod.data_out.connect(fifo.put_export);
cons.data_in.connect(fifo.get_export);
fork
run_test();
repeat(30) begin
$display("%0t: Show TOP FIFO level %0d of %0d", $time, fifo.used(), fifo.size());
#10;
end
#5us global_stop_request();
join
end
endmodule
uvm_tlm_fifo的实现简单模型
一個轉貼的例子
從http://electron64.blog.163.com/blog/static/1060339702011293395214/
這是uvm_tlm_fifo內部機制的原型
我們可以看到uvm_tlm_fifo內部的機制是採用mailbox來實作的
在tlm_fifo中，运行了两个进程，这两个进程通过mailbox进行同步。他们分别对应了get_t()和put_t()。 可以通过`define VERBOSE看tlm_fifo中函数调用状况。
從http://electron64.blog.163.com/blog/static/1060339702011293395214/
這是uvm_tlm_fifo內部機制的原型
我們可以看到uvm_tlm_fifo內部的機制是採用mailbox來實作的
在tlm_fifo中，运行了两个进程，这两个进程通过mailbox进行同步。他们分别对应了get_t()和put_t()。 可以通过`define VERBOSE看tlm_fifo中函数调用状况。
1 /**
2 ** tlm_fifo.sv
3 ** 说明： 通过简单的模型来阐述 UVM/OVM中TLM uvm_tlm_fifo
4 ** 的基本原理。直接编译运行即可。
5 ** 作者：http://electron64.blog.163.com
6 */
7 virtual class port_base#(type T=int) ; // 构造一个抽象类
8 typedef port_base#(T) this_type;
9 protected this_type port_handle; // 申明一个对象句柄（指针）
10
11 virtual task get_t(output T trans);
12 endtask // 虚函数，get_port和get_imp都必须以它为基类
13 virtual task put_t(T trans); // 虚函数，put_port和put_imp都必须以它为基类
14 endtask
15 function void connect(this_type port); // connect仅仅是实现对象句柄的赋值
16 port_handle = port;
17 endfunction // connect
18
19 endclass // port_base
20
21 class get_port#(type T=int) extends port_base#(T);
22 virtual task get_t(output T trans);
23 port_handle.get_t(trans);
24 endtask // get_t
25 endclass // get_port
26
27 class get_imp#(type T=int, type IMP=int) extends port_base#(T);
28 local IMP m_imp; // imp表示具体实现get_t()函数的对象句柄。
29 function new(IMP imp);
30 m_imp = imp;
31 endfunction // new
32
33 virtual task get_t(output T trans);
34 m_imp.get_t(trans); // 调用实现对象对应的get_t()函数
35 endtask // get_t
36
37 endclass // get_imp
38
39 class put_port#(type T=int) extends port_base#(T);
40 virtual task put_t(T trans);
41 port_handle.put_t(trans);
42 endtask // put_t
43 endclass // put_port
44
45 class put_imp#(type T=int, type IMP=int) extends port_base#(T);
46 local IMP m_imp; // imp表示具体实现put_t()函数的对象句柄。
47 function new(IMP imp);
48 m_imp = imp;
49 endfunction // new
50
51 virtual task put_t(T trans);
52 m_imp.put_t(trans); // 调用实现对象对应的put_t()函数
53 endtask // put_t
54
55 endclass // put_imp
56
57 class tlm_fifo#(type T=int);
58 typedef tlm_fifo#(T) this_type;
59 put_imp#(T,this_type) put_export;
60 get_imp#(T,this_type) get_export;
61
62 local mailbox #(T) m;
63
64 function new();
65 m = new(1);
66 put_export = new(this);
67 get_export = new(this);
68 endfunction // new
69
70 virtual task put_t(T trans);
71 m.put(trans);
72 `ifdef VERBOSE
73 $display("[tlm_fifo.put_t]: Generate transaction:%d", trans);
74 `endif
75 endtask // put_t
76
77 virtual task get_t(output T trans);
78 m.get(trans);
79 `ifdef VERBOSE
80 $display("[tlm_fifo.get_t]: Get transaction:%d", trans);
81 `endif
82 endtask // get_t
83
84 endclass // tlm_fifo
85
86
87 class producer;
88 put_port#(int) m_put_port;
89 function new();
90 m_put_port = new();
91 endfunction // new
92
93 task run(int num=10);
94 int trans;
95 for(int i=0; i
96 trans = $random;
97 #5 m_put_port.put_t(trans);
98 $display("@%0t [Producer]: Generate transaction:<%0d>", $time, trans);
99 end
100 endtask // run
101 endclass // producer
102
103 class consumer;
104 get_port#(int) m_get_port;
105 function new();
106 m_get_port = new();
107 endfunction // new
108
109 task run(int num=10);
110 int t;
111 t = -1;
112 for(int i=0; i
113 #i m_get_port.get_t(t);
114 $display("@%0t [Consumer]: Get transaction:@{%0d}@", $time, t);
115 end
116 endtask // run
117 endclass // consumer
118
119 module top;
120 producer p;
121 consumer c;
122 tlm_fifo f;
123 initial begin
124 p = new();
125 c = new();
126 f = new();
127 c.m_get_port.connect(f.get_export); //通过句柄赋值进行连接
128 p.m_put_port.connect(f.put_export);
129 fork
130 c.run();
131 p.run();
132 join
133 #10 $finish;
134 end
135 endmodule
136
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