Display apparatus, upgrading apparatus, display system and data processing method of display system

A display system comprising:

• a display apparatus which comprises a first data processor to perform a first data processing, a display unit to output processed data, at least one first signal connector to transmit and receive data and a first controller to control the first data processor;
• and
• an upgrading apparatus which comprises at least one second signal connector connected to the first signal connector to connect to the display apparatus, a second data processor to perform a second data processing, and a second controller to control the second data processor,
• wherein the first data processor and the second data processor perform the data processing independently,
• wherein the first controller controls the display unit to display a screen based on the processed signal received from the upgrading apparatus via the first signal connector, and
• wherein the first controller controls to display a certain screen based on information received from the upgrading apparatus while the second controller controls the second data processor to upgrade a main user interface or load a program.