National COP400
Developer	National Semiconductor
Manufacturer	National Semiconductor
Type	microcontrollers
Production	1977
ISA	COP400
Word size	4 bit 0.5 octets 1 nibbles
Technology	nMOS, CMOS
Clock	4.098 kHz-500 kHz
Package	DIP16, DIP24, DIP28, DIP40

The COP400 or COPS II or simply COPS (Controller Oriented Processor System II) was a family of 4-bit microcontrollers developed by National Semiconductor. The family was introduced a year after the COPS I in 1977. Components in the COPS II were made in nMOS and CMOS technology instead of pMOS as used in COPS I. The COPS II obsoleted the COPS I family soon after release.

2nd sources

National Semiconductor, while almost exclusively never 2nd sourcing their own designs, did license the COPS II to Western Digital in 1980. WD continued manufacturing the COPS II until 1984 when they moved into the data storage market.

Members

Part	ROM	RAM	Frequency	Package	Notes
COP402		256 b	250 kHz - 500 kHz	DIP40	ROM-less version of COP420, for prototyping
COP402M		256 b	250 kHz - 500 kHz	DIP40	ROM-less version of COP420, for prototyping, for MICROBUS
COP404L		512 b	250 kHz - 500 kHz	DIP28	ROM-less version of COP444L, for prototyping
COP10L	512 B	128 b	4.098 kHz - 62.5 kHz	DIP24
COP11L	512 B	128 b	4.098 kHz - 62.5 kHz	DIP16
COP420	1,024 B	256 b	250 kHz - 500 kHz	DIP28
COP420L	1,024 B	256 b	62.5 kHz - 250 kHz	DIP28	Low-power version
COP420C	1,024 B	256 b	4.098 kHz - 62.5 kHz	DIP28	CMOS version
COP421	1,024 B	256 b	250 kHz - 500 kHz	DIP24	Identical to COP420, but DIP24
COP421L	1,024 B	256 b	62.5 kHz - 250 kHz	DIP24	Low-power version
COP444L	2,048 B	512 b	250 kHz - 500 kHz	DIP28	Identical to COP420, twice the memory (2xROM/2xRAM)
COP445L	2,048 B	512 b	250 kHz - 500 kHz	DIP24	Identical to COP444L, but DIP24
DIP28 and DIP24 chips are architecturally identical; 4 IN ports are simply omitted on the smaller package.

Design

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COP400 ISA

Main article: COP400 ISA

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Documents

• National COPS400 Databook

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