byucc.jhdl.apps.Stimulator
Interface ValueProvider

All Known Subinterfaces:

BooleanValueProvider, BVValueProvider, IntegerValueProvider, LongValueProvider

All Known Implementing Classes:

Pulse, Random

public interface ValueProvider

Interface that marks a class as being able to provide values for the interactive stimulator. See the subinterfaces of this interface, such as BVValueProvider

Author:

Anthony L. Slade

Method Summary

java.lang.String	getForceSchedule(int radix) Used by Stimulator to get a nicely printed view of the function or series of values that are scheduled to be put on the wire
java.lang.String	getForceSchedule(java.lang.String format) Used by Stimulator to get a nicely printed view of the function or series of values that are scheduled to be put on the wire
boolean	isDrivingOutput() This method is used if the wire being driven is a tri-state bus wire.

Method Detail

getForceSchedule

public java.lang.String getForceSchedule(int radix)

Used by Stimulator to get a nicely printed view of the function or series of values that are scheduled to be put on the wire

Parameters:

radix - the custom ValueProvider may use this value to change the radix in which values will be shown in the schedule

getForceSchedule

public java.lang.String getForceSchedule(java.lang.String format)

Used by Stimulator to get a nicely printed view of the function or series of values that are scheduled to be put on the wire

Parameters:

format - the custom ValueProvider may use this value to change the way values are shown in the schedule. This parameter is meant to be a BV format string.

isDrivingOutput

public boolean isDrivingOutput()

This method is used if the wire being driven is a tri-state bus wire. States whether the cell is driving the tri-state output. This method is only called if the wire is associated with TriStateStimulator. In most cases, it is best to simply return true, unless you know that you don't want to drive the wire at a certain time. When driving a tri-state bus, this method is queried on every clock step (a clock cycle is built of various clock steps, based on the number and composition of all of the clock schedules given to clock drivers), regardless of whether or not the getNextValue method is called. The getNextValue method is called only once per rising clock edge (or falling edge if the user has set the Stimulator to be a falling-edge-triggered cell). Therefore, it is up to the implementation of the ValueProvider to determine when the Stimulator should drive the bus or if it should let other cells drive it (or just let it float). Usually, implementations of this method will remember the last value put to the wire (i.e. the last value given by the getNextValue method) and base the return value of this method on that last value put. Hence, if the clock schedule is 1100, the getNextValue method will be called (for rising-edge triggered) on the first step of the schedule (the first 1). Then the isDrivingOutput method will be called on the next three steps of the clock. If the value that was put on the first step is to be maintained through the next three steps as well, the isDrivingOutput method should remember that and return true.
Note that no matter the value returned by isDrivingOutput, the getNextValue method will be called on every pertinent edge of the clock, but if the wire is a tri-state bus, the Stimulator will not attempt to drive it if isDrivingOutput returns false.

Returns:

true if the driver is presently driving the output.