Scan chain circuitry on an integrated circuit device includes a plurality of memory elements, and a plurality of control elements. Each of the control elements is located between respective ones of the plurality of memory elements for controllably connecting the plurality of memory elements into a scan chain. A plurality of respective scan enable activation elements controls a respective subplurality of the plurality of control elements for connecting a respective subplurality of the plurality of memory elements into the scan chain. Each scan enable activation element is actuated, to connect its respective subplurality of the plurality of memory elements into the scan chain, by a first enable signal common to more than one of the scan enable activation elements, and a second enable signal for that one of the scan enable activation elements. Such scan chain circuitry may be used for entering configuration data into a programmable integrated circuit device.