The '''μCOM-4''' line is a [[microprocessor family|family]] of [[4-bit architecture|4-bit]] [[microcontroller]]s developed by [[NEC]] in the late 1970s. This family was designed to be low-cost, mass-produced, [[microcontroller]]s for [[electronic cash register|ECRs]], industrial controllers, appliance controllers, games, toys, scientific calculators, and other consumer electronics.

===Introduction Date===

==Lines==

The '''μCOM-42''' (also referred to as '''{{nec|μPD548C}}''') was specifically marketed for [[electronic cash register]]s (ECRs), [[Point of Sale]] (POS), and [[electronic scale]] applications. The μCOM-42 chips were specifically designed for controlling 8x4 keyboards, 8-digit displays, and various ECR-type printers.

 

The single-chip had single-byte 72 instructions with a 10[[µsec]] instruction cycle. The chip included 1920x10-bit [[program memory]], 96x4-bit [[data memory]], 4-level [[hardware stack|stack]], 2 [[interrupt request|interrupt request lines]], and various I/O ports.

 

The '''μCOM-43''' (also referred to as '''{{nec|μPD546C}}''') was marketed as a general-purpose microcontroller suited for a large array of low-cost consumer and industrial applications.

The single-chip had 80 general instructions with a 10[[µsec]] instruction cycle. The chip included 2000x8-bit [[program memory]], 96x4-bit [[data memory]], 3-level [[hardware stack|stack]], various [[interrupt request|interrupt request lines]] and 35 I/O ports.

===μCOM-44===

The '''μCOM-44''' (also referred to as '''{{nec|μPD547C}}''') was marketed as a low cost general-purpose microcontroller suited specifically well for various controllers due to its large amount of I/O ports, similar to the μCOM-43.

The single-chip had a reduced 58 general instructions with a 10[[µsec]] instruction cycle. The chip included a reduced [[program memory]] of 1000x8-bit, reduced [[data memory]] of 64x4-bit, a single-level [[hardware stack|stack]], but a large set of 35 I/O ports.

===μCOM-45===

The '''μCOM-45''' (also referred to as '''{{nec|μPD550C}}''') was the low-end, ultra low cost general-purpose microcontroller suitable for  mass-produced extremely low cost consumer products.

Like the μCOM-44, the μCOM-45 had a reduced instruction set of 58 instructions with a 10[[µsec]] instruction cycle. The chip included a reduced [[program memory]] of 640x8-bit, reduced [[data memory]] of 32x4-bit, a single-level [[hardware stack|stack]], and only 21 I/O ports.

===μCOM-75===

The '''μCOM-75''' series were introduced in early 1980 made in [[CMOS]] technology and had comparable features to the previous ''μCOM-4'' product line.

[[Category:NEC]]