The Z86C21 microcontroller is a member of the Z8® single-chip microcontroller family with 8KB of ROM and 236 bytes of RAM. The device is packaged in a 40-pin DIP, 44-pin PLCC, or a 44-pin QFP format with a ROMless pin option available on the 44-pin versions only. With the ROM/ROMless feature selection, the Z86C21 MCU offers both external memory and preprogrammed ROM, making the Z86C21 MCU well-suited for high-volume applications or where code flexibility is required.