... It includes micro-controllor, 1MBytes SRAM, 2Mbytes flash memory, voltage regulator, 2 channels DB-9 serial port connector, 1 USB ... IC controlledProvide schematic diagram and easy design for PCBFunction feature:Memory : Program memory connects 2PCS 512KB SRAMs, enable signal is /CE1, ... /CE2; Data memory connects 1MB flash memory, enable signal is /CE3NKeypad : 4x4 size, P2 ...