An apparatus and method for transferring data from a source memory to a transmit buffer memory and then from the transmit buffer memory at a particular rate. A current time counter advances at the rate at which data is to be transmitted from the transmit buffer memory to the interface. A schedule memory stores entries, each valid entry being associated with data that is to be transmitted from the transmit buffer memory to the interface. A timestamp is associated with each valid entry in the schedule memory. Circuitry is then operative on each valid entry read from the schedule table to generate a request for a data transfer between the source memory and the transmit buffer memory; perform a data transfer from the source memory to the transmit buffer memory in response to the request; and transfer the data from the transmit buffer memory when the current time circuitry output reaches a value representing at least the same point in time that is represented by the timestamp associated with the entry for which the request was generated.