78K


78K is the trademark name of 16- and 8-bit microcontroller family
manufactured by Renesas Electronics, originally developed by NEC
started in 1986.
The basis of 78K Family is an accumulator-based register-bank CISC architecture.
78K is a single-chip microcontroller, which usually integrates; program ROM, data RAM, serial interfaces, timers, I/O ports, an A/D converter, an interrupt controller, and a CPU core, on one die.
Its application area is mainly simple mechanical system controls and man-machine interfaces.
Regarding software development tools, C compilers and macro-assemblers are available.
As for development tool hardware, full probing-pod type and debug port type in-circuit emulators,
and flash ROM programmers
are available.
Historically, the family has 11 series with 9 instruction set architectures. As of 2018, 3 instruction set architectures, those are 8-bit 78K0, 8-bit 78K0S, and 16-/8-bit 78K0R, are still promoted for customers' new designs.
But in most of cases, migration to RL78 Family,
which is a successor of 78K0R and almost binary level compatible with 78K0R,
is recommended.

Variants

78K0 Series

is a long-running 8-bit single chip microcontroller,
which is the basis of 78K0S and 78K0R Series. It contains 8× 8-bit registers ×4 banks. For 16-bit calculating instructions, it performs ALU operation twice. Each instructions are performed serially without instruction pipelining. It has 16-bit 64K Byte address space. Some variants of 78K0 have affordable and compact type 8-bit R-2R D/A converter, which does not have monotonicity because it is not trimmed for adjustment nor followed by operational amplifier.
In its earlier stage, the Program Memory was one-time PROM, UV-EPROM, or mask ROM.
But with the times, it became flash memory.
Renesas official:

78K0S Series

78K0S Series is a low-end version of 78K0.
It has 8× 8-bit registers, but without any banks. In addition, some instructions, such as multiplication and division, are removed from 78K0 instruction set architecture.

78K0R Series

78K0R Series is a 16-bit single-chip microcontroller with 3-stage instruction pipelining.
Its instruction set is similar to 78K0 and covers 16- and 8-bit operations. It has 20-bit 1M Byte address space. 75 instructions out of 80 are identical with that of RL78 Family; its successor.

178K0 Series

178K0 Series is a successor of NEC's 17K Family 4-bit microcontroller for DTS and remote controls.
It integrates 17K family's peripheral functions with the 78K0 8-bit CPU core on a chip.

178K0S Series

178K0S Series is also a successor of 17K Family with the 78K0S CPU core.

78K4 Series

78K4 Series is a 16-bit single-chip microcontroller with 16 and 8-bit operations.
It has 16× 8-bit registers ×4 banks, which can be also used for 8× 16-bit registers ×4 banks. Some of these registers can be also used as 24-bit extension for addressing modes. It has 24-bit 16M Byte address space. It has microcode-based operations named Macro Service with interrupt functions.

78K7 Series

78K7 Series is a 32-bit single-chip microcontroller with 32, 16 and 8 bit operations. It has 8× 32-bit registers ×16 banks, which can be also used for 16× 16-bit registers ×16 banks and 16× 8-bit registers ×16 banks. It has microcode-based operations named Macro Service with interrupt functions. It has 24-bit 16M Byte linear address space. It is used for some Quantum Fireball products,
but shortly replaced with V850 Family 32-bit RISC microcontrollers.

78K6 Series

78K6 Series is a 16-bit single-chip microcontroller. Its life-time was short, and less variants.

78K1 Series

78K1 Series is an 8-bit single-chip microcontroller. It has 8× 8-bit registers ×4 banks. 78K1 series is targeted for servo controls of videocassette recorders. μPD78148 sub-series integrates 2 operational amplifiers.

78K3 Series

78K3 Series is a 16-bit single-chip microcontroller with 16 and 8 bit operations. It has 16× 8-bit ×8 banks, which can be also used for 8× 16-bit registers ×8 banks. Its address space is 16-bit 64K Byte. It is developed as high-end series of 78K Family. It has microcode-based operations named Macro Service with interrupt functions.
This series is used for hard disk drives, especially Quantum Fireball Series.
μPD78364 sub-series is used for inverter compressor controls.
It is also used for traction control systems of some cars.

78K2 Series

78K2 Series is an 8-bit single-chip microcontroller. It has 8× 8-bit registers ×4 banks. It is developed as general purpose series of 78K Family.

Predecessors

87AD Family

87AD Family is an 8-bit single-chip microcontroller. It has 8× 8-bit registers ×4 banks. Its instruction set architecture became the basis of 78K.

17K Family

17K Family is a 4-bit single-chip microcontroller, especially dedicated for DTS and remote controls. It has 2 plane of 128× 4-bit register files, and sophisticated fully orthogonal instruction set. This instruction set is completely different from that of 78K Family.

Table list of 78K Family