Display drivers

Direct accessible frame buffer means the frame buffer is accessible directly via data- and address bus. For that case the driver GUIDRV_Lin could be used. This driver supports all display controllers with linear video memory accessible via direct interface. The driver does only manage the content of the video memory. It is independent of the register interface of the display controller and can be used for managing each linear mapped video memory.

Whereas the direct interface accesses the video memory directly by the address bus of the CPU, the indirect interface requires a more complex communication with the display controller to get access to the video memory. On LCD controller side that interface is often called "MPU" interface. It normally consists of a set of control- and data lines. on emWin side this requires a few simple communication routines. These are getting called for writing and reading operations to/from the LCD controller.