1. A method for providing an external clock signal to an external clock input of a synchronous memory comprising the following steps: (a) holding the external clock signal in an idle state; (b) upon start of a transaction with the synchronous memory, activating the external clock signal, the clock signal when active functioning as a periodic timing reference clock; (c) keeping the external clock signal active during the transaction; and, (d) upon completion of the transaction, returning the external clock signal to the idle state.