Technical data

Basic VHDL simulation

Tutorial: Using ModelSim PE Getting Started with ModelSim PE

Step 25.

Examine the current value of the signal count by entering the command:

examine count

You can also see this information in the Signals window.

Step 26.

You can find out what kind of variable or signal count is by using the Model

Sim

command

describe

. To see this, enter:

describe count

The system should report (in the Transcript window) that count is an 8-bit array of an

enumerated type:

Step 27.

Click

OVER

(for Step Over) in the tool bar to step over this instruction. If you had clicked

STEP instead, the simulation would have entered the increment function called in line 35.

Step 28.

Re-examine the value of count and notice that its value has not changed. Even though the signal

count has been assigned a new value, the counter has not yet been incremented. This is because

a signal assignment does not take effect until after any specified propagation delays (specified

using an after clause in its VHDL signal assignment statement).

Step 29.

Again, select

CONT

to resume the run.