Posted on September 11, 2016 at 23:10The external memory and LCD interfaces are pin hogs. The parts share a common die packaged in a multitude of form-factors. Low pin count devices cannot escape all functionality. The device Data Sheet should make it sufficiently apparent about what pins do or don't escape the package, and what AF (alternate function) multiplexors are associated with specific pins and functionality.
It would not surprise me that a 100-pin device is incapable of providing fully functionality to the LCD, and some subset, or altered palette, might be required. You have a better chance with the 144-pin variants.
