I am trying to interface 7" 800x480 TFT resistive touchscreen LCD based on SSD1963 using STM32F051R8T6( from the discovery). My aim is to write images onto an external NAND flash memory and read the images on to the LCD screen. The problem is the screen update rate(time required for screen fill) is very long about 3-5 seconds. I would like to have answers to my following queries:
1) What is the next best economic ST microcontroller that can give decent performance for my application(not directly going for the high end ones)?
2) What parameter of a microcontroller specs should be considered while selecting for GUI based applications?