In Texas, if you are charged with a felony, and have been indicted, within 180 days of the date of the indictment the state must be able to move forward to trial. If the state is no so ready, then the defendant must file a motion to dismiss citing the length of time that has passed since the commencement of the proceedings and the violation of the defendant's 6th Amendment rights. There are execptions to this time period that can extend the period of time the state has, but that is the basic gist.
Additional information: The state has 90 days from the date of arrest on a felony charge to return an indictment if the person is in jail and 180 days from arrest if the person is on bond. If the state misses the 90 day date, the defendant is entitiled to release on personal recognizance.