LOS ANGELES, California (CNN) -- Television personality Nicole Richie was sentenced Friday to serve 90 hours in jail for driving under the influence in December.

Richie, 25, was sentenced to 96 hours, or four days, but was given credit for the six hours she has already served in jail. She will also be on probation for three years, and was fined $2,048.

It was not immediately known where the time would be served.

Richie entered the courtroom in Glendale, California, on the arm of her boyfriend, Good Charlotte band member Joel Madden. Watch as Richie goes to court »

Superior Court Commissioner Steven K. Lubell warned Richie that she would go to jail for a year if she violates her probation.

She was ordered to enroll in a second-offender drug and alcohol program and must prove that she completed it by February 20, 2008.

"You are not to drive with any measurable amount of alcohol or drugs in your system," Lubell told her. "You are not to drive without a driver's license."

Richie was arrested in December after motorists spotted her SUV going the wrong way on the 134 freeway in Burbank, California, and called 911.

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