The output resolution of the VGA signal is 640x480. The text mode grid is 80x60. The microcontroller used in the circuit description is a softcore Microblaze. The microcontroller embeds a UART controller so that the display can be drived through an external source.
I've used my character set from my LCDSim project to test the system. Every character is draw on 8x8 pixel area, so a font pack 8x8 should be used.