如何在sequence里访问component或interface
时间: 2023-09-20 22:01:57 浏览: 93
要在Sequence里访问component或interface,首先需要了解Sequence图的基本结构和符号。
在Sequence图中,一个对象被表示为一个位于顶部的长方形框,这个框被称为Lifeline(生命线)。Lifeline代表了一个实例或角色,它与系统中的其他对象进行交互。
要访问一个component或interface,我们可以使用箭头来表示消息的流向。有两种不同的箭头可以在Sequence图中使用:实线箭头和虚线箭头。
对于component的访问,我们可以使用实线箭头来表示消息的流向。从一个对象的Lifeline指向另一个对象的Lifeline的实线箭头代表一条同步消息。这表示第一个对象调用了第二个对象的操作或方法。
对于interface的访问,我们可以使用虚线箭头来表示消息的流向。从一个对象的Lifeline指向另一个对象的Lifeline的虚线箭头代表一条异步消息。这表示第一个对象发送了一条消息给第二个对象,但不必等待它的响应。
通过使用这些箭头,我们可以在Sequence图中清楚地表示对象之间的交互和通信。根据需要,我们可以使用多个箭头来表示不同步骤中的消息流。
总而言之,在Sequence图中访问component或interface,需要使用实线箭头表示同步消息,使用虚线箭头表示异步消息。这样可以很好地展示对象之间的交互和通信。
相关问题
1. Draw a UML sequence diagram that models the following events in a three-tier database client-server architecture: The client applet sends a connection request to the database servlet, which sends back a password request. The user supplies a username and password, which are sent back to the database servlet. The username and password are correct, so the servlet responds with an "OK" message. The user enters search parameters in the applet interface, and the client applet translates these into an SQL query, which is sent to the database servlet. The database servlet sends the SQL query to the remote database, which sends back the results of the query. The servlet passes the results back to the client applet.
Sure, here is a UML sequence diagram that models the events you described:
```
Client Applet Database Servlet Remote Database
| | |
|----> Connection Request ---->| |
| |<---- Password Request ------|
| Username & Password | |
|<---- Password Challenge -----| |
| |----> Validation Request ---->|
| | Username & Password |
| |<----- Validation Result ----|
| Search Parameters & SQL | |
|----> SQL Query Request ---->| |
| |----> SQL Query Request ---->|
| | SQL Query |
| |<----- Query Results --------|
|<---- Query Results ---------| |
```
In this diagram, each horizontal line represents an object or component in the system, and the vertical arrows represent messages being passed between them. The arrows are labeled with the message name and any parameters being passed. The diagram shows the flow of events from the client applet's initial connection request through to the retrieval of query results.
写一个uvm环境,在monitor中检测当前bit和改bit的补码值,然后在scoreboard中进行比对
以下是一个基本的UVM环境,包含一个monitor和一个scoreboard,用于检测当前bit和改bit的补码值:
```systemverilog
`include "uvm_macros.svh"
class my_env extends uvm_env;
my_agent m_agent;
my_scoreboard m_scoreboard;
function new(string name = "my_env", uvm_component parent);
super.new(name, parent);
endfunction : new
function void build_phase(uvm_phase phase);
super.build_phase(phase);
m_agent = my_agent::type_id::create("m_agent", this);
m_scoreboard = my_scoreboard::type_id::create("m_scoreboard", this);
endfunction : build_phase
function void connect_phase(uvm_phase phase);
super.connect_phase(phase);
m_agent.monitor_ap.connect(m_scoreboard.analysis_export);
endfunction : connect_phase
endclass : my_env
class my_monitor extends uvm_monitor;
uvm_analysis_port#(my_analysis_item) analysis_port;
my_analysis_item analysis_item;
function new(string name = "my_monitor", uvm_component parent);
super.new(name, parent);
endfunction : new
virtual function void build_phase(uvm_phase phase);
super.build_phase(phase);
analysis_port = new("analysis_port", this);
endfunction : build_phase
virtual task run_phase(uvm_phase phase);
super.run_phase(phase);
while(1) begin
// Read current bit and its two's complement
bit curr_bit = my_interface.read_bit();
logic signed [31:0] curr_twos_comp = $signed(curr_bit) ? -1 - curr_bit : curr_bit;
// Wait for change in bit value
@(my_interface.posedge);
// Read changed bit and its two's complement
bit changed_bit = my_interface.read_bit();
logic signed [31:0] changed_twos_comp = $signed(changed_bit) ? -1 - changed_bit : changed_bit;
// Create analysis item and send to scoreboard
analysis_item = new("analysis_item");
analysis_item.curr_bit = curr_bit;
analysis_item.curr_twos_comp = curr_twos_comp;
analysis_item.changed_bit = changed_bit;
analysis_item.changed_twos_comp = changed_twos_comp;
analysis_port.write(analysis_item);
// Wait for next posedge
@(my_interface.posedge);
end
endtask : run_phase
endclass : my_monitor
class my_scoreboard extends uvm_scoreboard;
uvm_analysis_export#(my_analysis_item) analysis_export;
my_analysis_item analysis_item;
function new(string name = "my_scoreboard", uvm_component parent);
super.new(name, parent);
endfunction : new
virtual function void build_phase(uvm_phase phase);
super.build_phase(phase);
analysis_export = new("analysis_export", this);
endfunction : build_phase
virtual function void run_phase(uvm_phase phase);
super.run_phase(phase);
while(1) begin
// Wait for analysis item from monitor
analysis_export.get_next_item(analysis_item);
// Compare current bit and its two's complement with changed bit and its two's complement
if (analysis_item.curr_bit != analysis_item.changed_bit) begin
if (analysis_item.curr_twos_comp != analysis_item.changed_twos_comp) begin
`uvm_error("BIT_ERROR", $sformatf("Bit value changed from %0d to %0d, but two's complement changed from %0d to %0d", analysis_item.curr_bit, analysis_item.changed_bit, analysis_item.curr_twos_comp, analysis_item.changed_twos_comp))
end
end
end
endfunction : run_phase
endclass : my_scoreboard
class my_agent extends uvm_agent;
my_monitor monitor_ap;
function new(string name = "my_agent", uvm_component parent);
super.new(name, parent);
endfunction : new
virtual function void build_phase(uvm_phase phase);
super.build_phase(phase);
monitor_ap = my_monitor::type_id::create("monitor_ap", this);
endfunction : build_phase
endclass : my_agent
class my_analysis_item extends uvm_sequence_item;
bit curr_bit;
logic signed [31:0] curr_twos_comp;
bit changed_bit;
logic signed [31:0] changed_twos_comp;
`uvm_object_utils(my_analysis_item)
function new(string name = "my_analysis_item");
super.new(name);
endfunction : new
endclass : my_analysis_item
```
在这个环境中,`my_monitor`任务读取当前的bit和它的补码值,然后等待bit值的改变。一旦有改变,它读取新的bit和它的补码值,并创建一个`my_analysis_item`对象,其中包含了当前bit和改变的bit以及它们的补码值。然后,它使用`analysis_port`将该对象发送到`my_scoreboard`。
`my_scoreboard`在接收到`my_analysis_item`对象后,比较当前bit和它的补码值与改变的bit和它的补码值。如果bit值不同,那么它会检查补码值是否也不同。如果补码值也不同,那么它将在控制台上输出一条错误消息。
在`my_env`中,`my_agent`和`my_scoreboard`被创建,并通过`monitor_ap`和`analysis_export`连接起来。然后,整个环境可以被实例化并运行。