In some examples, a system includes a plurality of fluid ejection devices, a fluid ejection controller, and a plurality of data lines shared by the plurality of fluid ejection devices and connected between the fluid ejection controller and the plurality of fluid ejection devices. A first data line of the plurality of data lines communicates data of a first memory of a first fluid ejection device of the plurality of fluid ejection devices, and a second data line of the plurality of data lines communicates data of a second memory of the first fluid ejection device.