The right not to testify in your own defense is a fundamental right, guaranteed by the 5th Amendment. You can NEVER be compelled to become a witness against yourself in court, or be forced to give a statement to law enforcement.
In fact, an accused person has no obligation to put on any evidence at all. You do not have to testify nor call witnesses to testify on your behalf. The burden of proof is entirely on the State of Florida. The State of Florida must prove an accused person guilty beyond a reasonable doubt.
On the other hand, you have a right to testify in your own defense if you choose to. If you testify, you will be treated as any other witness. There is no special treatment for an accused person who becomes a witness in their own criminal case. If you have prior felony convictions or prior convictions for crimes of dishonesty, those convictions can be discussed before the jury. The judge will also instruct the jury that they are to evaluate your testimony the same way they would evaluate the testimony of any other witness.
In the Casey Anthony trial, currently winding down in Orlando, Florida, the judge will offer those same instructions to the jury if Ms. Anthony testifies, or if she choses not to testify.
Casey Anthony is charged with first-degree murder in the death of her 2-year old daughter. If convicted, she faces death by lethal injection.