Introduction

As an intro to the VisualDSP++ integrated development and debugger environment (VDSP++ IDDE) we will start with a "Hello World" example in C. First of all, we will develop software on the host PC system which will be loaded and run on the target system. Ideally we would be able to test our code without having to compile, load, and run on the target. Using the "simulation" mode of VDSP++, we can do just that.

But to build applications for the Blackfin, VDSP acts as a cross-compiler since it is compiled and runs on the host system but will build applications for the Blackfin.

Hello World Example

Figure 1. Hello World program.

To the left of the field named "NewProject" one of the buttons is highlighted blue -- this will rebuild all of the files that are part of an active project. Clicking this button causes the dialog box of Figure 2 to come up

Figure 2. Load Multiprocessor Confirmation.

The BF561 used a two-core processor, so you can develop multiprocessor code! If you click "OK" your code is loaded onto the EZKIT board. Figure 3 shows the result of running the code (F5 key).

Figure 3. Load Multiprocessor Confirmation.

As you'd think, the BF561 prints "Hello World!" to the Console window of the VDSP++ environment. Notice it's the core "Device 0:a" that does the printing. In a multiprocessor program, this designation could be useful for debugging. A pretty natural question is if scanf works, so Figure 4 shows the next program.

What's that, World?

Figure 4. scanf code.

When you run the program, you'll see the printf functions still print to the Console, but now a new dialog window comes up to take the standard input.

Figure 5. stdin dialog.

If you type something in you will see a Console similar to the one in Figure 6. (Of note is that the word I typed was 34 characters, but the code only supports 32 - and that the stdin input was not echoed.)

Figure 6. Result of scanf code.