Data processing system and image processing system

A data processor comprising:

• a plurality of processing modules;
• a control circuit;
• a plurality of terminals including first terminals, second terminals and an external device clock terminal,
• wherein one of said processing modules is a central processing unit and other is a graphic processing module for processing a graphic data,
• wherein said first terminals couple to a first synchronous memory,
• wherein said second terminal couples to a second synchronous memory,
• wherein said external device clock terminal outputs operation clock signals outside of said data processor, and
• wherein said control circuit controls a memory access to said first synchronous memory or to said second synchronous memory according to a request from said processing modules.