As you define waveform transitions, GPIF Designer automatically creates states in the top line—in this example,
the four states S0 through S3. This waveform is designed to repeat endlessly as it is designed to produce the
clock outputs. This is accomplished by branching from state 3 back to state 0. Branching to a state is done by
inserting a decision point in the Status line—click on the dotted clock line at the beginning of the decision state.
GPIF Designer inserts a diamond to signify the decision state. Right-clicking this diamond brings up a dialog box
that allows you to create a logic equation using two variables and three logical operators (AND, OR, XOR) for the
branch condition. An unconditional branch is created by selecting the same state as destination for if condition
check and for else condition.
Further Reading
For more information on GPIF, refer to Chapter 10 of the FX2LP Technical Reference Manual.
For information on interfacing RAM to GPIF of FX2LP, refer to Interfacing SRAM with FX2LP over GPIF -
AN57322.