Editing nec/μcom-4

{{nec title|μCOM-4}}
{{ic family
| extended family   = yes
| title             = NEC μCOM-4
| image             = <!-- Image representation of the IC family, e.g. "MCS-4.jpg"   -->
| caption           = <!-- description of the image                                  -->
| developer         = NEC
| manufacturer      = NEC
| type              = Microcontrollers
| production start  = October, 1977
| production end    = <!-- production end date, e.g. "January 1, 1985" or "1973"     -->
| arch              = 4-bit
| word              = 4 bit
| proc              = <!-- process, e.g. "8 μm"                                      -->
| tech              = pMOS
| tech 2            = CMOS
| clock min         = 150 kHz
| clock max         = 440 kHz
| package           = DIP28
| package 2         = DIP42
}}
The '''μCOM-4''' (or uCOM-4) line is an [[microprocessor family|extended 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. The μCOM-4 line is based on the {{nec|μPD751}}, the first Japanese single-chip microprocessor.

==Introduction Date==
{| class="wikitable"
! colspan="4" | 1977 !! colspan="4" | 1980
|-
! Q1 !! Q2 !! Q3 !! Q4 !! Q1 !! Q2 !! Q3 !! Q4 
|-
| {{nec|μCOM-42}} || {{nec|μCOM-43}} || {{nec|μCOM-44}} || {{nec|μCOM-45}} || || || {{nec|μCOM-75}} ||
|}

== Families ==
The μCOM-4 was original divided into two separate domains:

===μCOM-42===
The '''{{nec|μCOM-42}}''' 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 μCOM-42 had a separate, modified instruction set, compared with the rest of the μCOM-4 families.

===μCOM-43/44/45===
The '''{{nec|μCOM-43}}/{{nec|μCOM-44|44}}/{{nec|μCOM-45|45}}''' was marketed as a general-purpose microcontroller suited for a large array of low-cost consumer and industrial applications. These MCUs shared a common instruction set.

* '''{{nec|μCOM-43}}''' - high-end family of MCUs, offering complete support for the entire [[/isa|μCOM-4 ISA]].
* '''{{nec|μCOM-44}}''' - mid-range family of MCUs, providing a subset of 58 instructions at a reduced cost.
* '''{{nec|μCOM-45}}''' - low-end family of MCUs, providing a subset of 58 instructions and less memory at the cheapest price.

== Design ==
{{empty section}}

== Instruction set ==
{{main|/isa|l1=μCOM-4 ISA}}
The family was originally split into two sets of ISAs. The {{\|μCOM-42}} had an instruction set specifically designed to facilitate its use in [[Electronic Cash Register]] (ECR) and Scale products. The {{\|μCOM-43}}/{{\|μCOM-44|4}}/{{\|μCOM-45|5}} were designed to be general purpose microcontrollers.

== See also ==
* {{nec|μCOM-8}}


{{stub}}
{{DEFAULTSORT:μCOM-4}}
[[Category:nec]]
[[Category:4-bit microprocessors]]
[[Category:1977 microprocessors]]
[[Category:microprocessor families]]
designer	NEC +
full page name	nec/μcom-4 +
instance of	microcontroller extended family +
main designer	NEC +
manufacturer	NEC +
name	NEC μCOM-4 +
package	DIP28 + and DIP42 +
technology	pMOS + and CMOS +
word size	4 bit (0.5 octets, 1 nibbles) +