All pins going to the display are outputs from the microprocessor. The display has no output pins.
RST is toggled low briefly once during initialisation to reset the display then left high.
CS will be set low to select the display and will remain low. However, for the Arduboy FX, CS will be pulled high when the serial EEPROM chip needs to be accessed.
D/C will be will be set low when a command needs to be sent to the display. It will be high when data is being sent, which is most of the time.