edsim51sh.ports
Class PortLatches

java.lang.Object
  edsim51sh.ports.PortLatches

public class PortLatches
extends java.lang.Object

This class is provided as a convenience to the target board programmer. An instance of this class contains the status of the 8051 port latches at a given time. This instance is passed to the TargetBaord.writeToPortPins() method, the method called during each execution of an 8051 instruction. The target board programmer must write an implementation for the abstract method TargetBaord.writeToPortPins(). In doing so, the instance of PortLatches can be examined to ascertain the status of each latch.
See TargetBoard.writeToPortPins() for more details.

getLatch

public boolean getLatch(int portNumber,
                        int pinNumber)

This method returns the status of a port latch, given the port number and pin number.

Parameters:

portNumber - A number between 0 and 3, corresponding to P0, P1, P2 and P3 on the 8051. The value in portNumber is ANDed with 3 (11 in binary) to force it to a value between 0 and 3.

pinNumber - A number between 0 and 7, corresponding to the pin numbers of a given port. The value in pinNumber is ANDed with 7 (111 in binary) to force it to a value between 0 and 7.

Returns:

true if the latch is at logic 1, false if it's at logic 0.