UPD78312AA Datasheet PDF - NEC => Renesas Technology

16/8 BIT SINGLE-CHIP MICROCONTROLLER

The μPD78312A(A) is a CMOS 16/8-bit microcomputer. It contains a high-performance 16-bit CPU, enabling highly advanced internal arithmetic/logical operations. Up to 56K bytes of external memory can be added.
The μPD78310A(A) is a ROM-less version of the μPD78310A(A), and can directly access external memory of up to 64K bytes. The μPD78310A(A) and μPD78312A(A) are members of the 78K/III series.
With the μPD78312A(A), the μPD78P312A, which contains a one-time PROM or EPROM, is also available for system evaluation.