idv_timer_sim Class Reference

Simulation Countdown Timer. More...

Inheritance diagram for idv_timer_sim:

Public Member Functions
	new (time countdown_time, string name="IDV Timer", bit autostart=0)
	Constructor.
void	show ()
	Show Show the member variable contents.
void	start_timer ()
	Start Timer.
void	stop_timer ()
	Stop Timer.
void	reset_timer ()
	Reset Timer.
void	restart_timer ()
	Restart Timer.
virtual void	alarm ()
	Alarm.
virtual void	fatal_error (string msg="")
	Fatal Error.
Public Attributes
string	m_name
	Name of this instance of timer - displayed with console messages.
Protected Attributes
bit	m_timer_running
	Timer is Running.
Private Member Functions
task	timer ()
	Timer Task - timer core.
Private Attributes
time	m_countdown_time
	Countdown Time - time to countdown from.
time	m_split_time
	Split Time - time at stop.
event	m_stop_timer
	Stop Timer Event - stop the timer.
event	m_reset_timer
	Reset Timer Event - reset to countdown_time.

Detailed Description

Simulation Countdown Timer.

This class is a simulation countdown timer. This timer behaves like an 'egg timer' for simulation time. We say simulation time to differentiate from a 'wall time' countdown timer.
Timer behaves like a stopwatch countdown 'egg timer.' It can started, stopped, restarted (from stopped time), and reset to the initial time.

Usage:

Where to Use:

use anywhere that you want to timeout after a specific amount of simulation time.
For example:

set a limit on how long you want you testcase to run by putting a timer in your environment
use in a bfm to time out if a specific signal wasn't recieved in time
use to do something after the time expires -- by reimplementing the alarm() method in a class that you derive from this class

How to Use:

construct the timer: set the amount of time to countdown; and select whether you want the timer to start counting immediately

        idv_timer_sim mytimeout;
        mytimeout = new(50 ns, "timer name"); // set timeout to 100ns, name 'timer name', do not autostart

stop - stop the timer at its current time
```
        mytimeout.stop_timer();
```
start - start the timer -- continue countdown from where the timer was last stopped
```
        mytimeout.start_timer();
```
reset - reset the timer to the original value
```
        mytimeout.stop_timer();
```
restart - restart the timer; set to the original value and then start the countdown
```
        mytimeout.restart_timer();
```

set a new timeout value -- by constructing a new instance

        mytimeout = new(50 ns, "timer name", 1);  // set timeout to 50 us, name 'timer name' and immediately start countdown timer

Definition at line 95 of file idv_timer_sim.sv.

Member Function Documentation

void idv_timer_sim::alarm ( ) [virtual]

Alarm.

Defines what happens when the countdown time expires.
Method defined virtual - so a derived class handle can redefine what happens in the event of an alarm.
For example: if the timer is to be used in a VMM environment - then extend the timer class and redefine this method with a vmm_log and a vmm_fatal or vmm_error call.

Returns:: void

Reimplemented in idv_timer_sim_vmm, idv_watchdog_sim_vmm, and idv_watchdog_sim.

Definition at line 286 of file idv_timer_sim.sv.

void idv_timer_sim::fatal_error ( string msg = "" ) [virtual]

Fatal Error.

Defines what happens when a fatal error occurs in the base class (this class).
Method defined virtual - so a derived class handle can redefine what happens in the event of a fatal error.
For example: if the timer is to be used in a VMM environment - then extend the timer class and redefine this method with a vmm_log and a vmm_fatal call.

Returns:: void

Reimplemented in idv_timer_sim_vmm, idv_watchdog_sim_vmm, and idv_watchdog_sim.

Definition at line 294 of file idv_timer_sim.sv.

idv_timer_sim::new	(	time	countdown_time,
		string	name = `"IDV Timer"`,
		bit	autostart = `0`
	)

Constructor.

Class Constructor

Parameters:

	countdown_time	time - Time to countdown from
	name	string - Name of this instance of timer - displayed with console messages
	autostart	bit - Start timer on construction (defaults to off)

Reimplemented in idv_timer_sim_vmm.

Definition at line 195 of file idv_timer_sim.sv.

void idv_timer_sim::reset_timer ( )

Reset Timer.

Reset the timer.
If the timer is running stop and reset the timer.
If the timer is not running just reset the timer.

Returns:: void

Definition at line 265 of file idv_timer_sim.sv.

void idv_timer_sim::restart_timer ( )

Restart Timer.

Restart the Timer
Start the timer over - resets and then starts the timer from the original countdown timme

Returns:: void

Definition at line 278 of file idv_timer_sim.sv.

void idv_timer_sim::show ( )

Show Show the member variable contents.

Returns:: void

Definition at line 207 of file idv_timer_sim.sv.

void idv_timer_sim::start_timer ( )

Start Timer.

Start the timer - forks off the timer task

Returns:: void

Definition at line 244 of file idv_timer_sim.sv.

void idv_timer_sim::stop_timer ( )

Stop Timer.

Stop the timer

Returns:: void

Definition at line 257 of file idv_timer_sim.sv.

task idv_timer_sim::timer ( ) [private]

Timer Task - timer core.

Forks off 3 threads:
1. Countdown timer: counts down and then sounds alarm
2. Thread waiting for stop: stops timer on stop event and stores split time for restart
3. Thread waiting for reset: resets timer on reset event

Definition at line 219 of file idv_timer_sim.sv.