Abstract: An integrated circuit includes a plurality of data handling devices and a data buffer for enabling transfer of data between the internal data handling devices and one or more external data handling devices external to the integrated circuit. A controller responds to an original clock signal for supplying a clock signal to control data transfer between the data handling devices. The controller includes a delay circuit operable to delay the original clock signal to generate a delayed clock signal, and includes a selector for inhibiting operation of the delay circuit and for selecting the original clock signal for controlling data transfer from an internal data handling device to another data handling device. The selector also enables operation of the delay circuit and selects the delayed clock signal for controlling data transfer from an external data handling device to an internal data handling device.