The G65SC816 is an advanced CMOS 16-bit microprocessor featuring total software compatibility with 8-bit NMOS and CMOS 6500 series microprocessors. The G65SC816 provides 24 address lines for 16 Mbyte addressing, while providing both 8-bit and 16-bit operation. This microprocessor contains an Emulation (E) mode for emulating 8-bit NMOS and CMOS 6500 Series microprocessors. A software switch determines whether the processor is in the 8-bit emulation mode or in the native 16-bit mode. This allows existing 8-bit system designs to use the many powerful features of the G65SC816.