Display device and method of controlling therefor

A method of controlling an operation of a display device (200, 600, 700) is described. The display device (200) includes a memory (720) including a self-refresh memory block, a display module and a controller (640, 710) configured to control the operation of the display device (200, 600, 700). The controller (200, 600, 700) is configured to receive a power-off signal, store a system booting file and a predetermined snapshot image in a self-refresh memory block based on a predetermined self-refresh mode, receive a power-on signal, boot a system by extracting the system booting file from the self-refresh memory block, and control the display module to display the predetermined snapshot image. A content is contiguously displayed by the display module (630) when the power-off signal is received. An image configured by default is displayed by the display module (630) after the power-on signal is received. A specific content is executed which is selected according to a user access frequency.