The LCD color depth and resolution defines the requirement for the image buffer to store data being displayed. This slide shows some typical configurations and memory requirement. The formula to calculate image RAM requirement is [(X resolution in pixels) * (Y resolution in pixels) * (number of colors) / 8] = Bytes per page of image buffer. For example, for monochrome, each pixel has only two settings - on and off. This requires only 1 bit per pixel. Looking at the 1/16th VGA resolution monochrome display, then we’ll need 160 x 120 x 1/8 bytes of image RAM, or 2400 bytes of data RAM for one page of image buffer. In the case of QVGA 18-bit color, each pixel needs 18-bits of data, or 320 x 240 x 18 /8 bytes of RAM assuming the digital logic can handle 18-bits. Using standard peripherals, either a 16-bit or an 8-bit interface can be used to get 24-bit data. The 24-bit data storage will waste some RAM. However, it is quite common to use 16-bits of data and not use the 2 LSBs in color depth without any significant impact on picture quality. In the case of 16-bit data, the common trend is to use 5 bits to represent Red, 5 for Blue and 6 for Green. The color QVGA resolution display requires the use of a significant amount of data RAM and a large amount of data movement. Because of this, traditional color graphics are considered to be in the high end 32-bit MCU domain application. However, the Microchip library makes it possible to do high quality graphics on low end 16-bit microcontrollers.