Intel MCS-48

Intel 8048   >>
Intel P8048H
Production:	1976 to 1990s
Producers: Intel Philips Semiconductors NEC Siemens AG
Processor clock:	6 MHz
Instruction set :	8 bit
Base:	40-pin DIP

MCS-48 is the name of a 1976 by Intel introduced family of 8-bit - microcontrollers . With a microcontroller, all parts of a computer system ( processor , program memory, data memory and input / output units) are ideally combined in a single module. The MCS-48 series is one of the first such systems. At the beginning it only had three members with the designations 8048, 8035 and 8748. With the 8035 the application program is in an external module, whereas with the 8048 and 8748 the application program is in the module itself - either in a mask-programmed ROM (8048) or in an EPROM (8748).

As early as 1980 with the introduction of the Intel 8051, a more powerful successor family was presented, which became known under the name MCS-51 . However, the success of the 8048 series in many areas of application ensured that it was still used extensively later and is even used today.

History and use

In 1978 the "low-cost" versions 8020, 8021 and 8022 appeared, which had fewer connections and therefore could only be operated with internal program memory. In the same year, the supplementary series of UPI-41 ( U niversal P eripheral I nterface) modules was presented. The 8-bit data bus is brought out directly here so that the processor can be used as a slave processor. Compared to the 8048 with 96 commands, the 8041 only has 90 commands. At the beginning the series only consisted of the two members with the designations 8041 and 8741, the most famous use is likely to be that of the 8042, which appeared later, as a keyboard controller in the IBM PC AT introduced in 1984 .

In 1978 the corresponding variants 8039 and 8049, in 1981 the 8749 with double ROM and RAM were presented.

Intel D8749

USSR clone of an Intel 8748

The family was initially manufactured using NMOS technology , and from the early 1980s onwards also using the CMOS technology that is common today .

Philips Semiconductors (now NXP ) had a license to manufacture this family and, based on the architecture, developed its own MAB8400 family. a. contained the first I²C interface and was used in the first Philips CD players (e.g. CD-100).

An 8048 was also used in Genius computer mice, which were popular in the 1980s, just as it was used as a co-processor in the Sinclair QL . MCS-48 components can still be found invisibly today in a myriad of devices, from bedside clocks to video recorders and washing machines.

architecture

The MCS-48 series is basically structured according to the Harvard architecture , with a separate input / output address space in addition to the program and data address space. The length of the program address is 12  bits , with which 4  KByte can be addressed. These are organized as two independent 2 Kbyte program banks. Since bank 2 is always external (exception 8050), additional program memory can be addressed by using output lines.

The internal data memory (64–256 bytes) can be expanded externally by another 256 bytes. The memory cells are designed to be static , they can be supplied with power via a standby supply line even when the device is switched off and thus receive the data.

In the simplest case, the input / output lines are expanded using the 8243 port extender module , which provides four 4-bit ports. The 8243 is integrated into the overall system with specially provided commands. In addition, standard MCS-80/85-I / O modules can be operated in the data address space.

During development, particular attention was paid to an instruction set that offers powerful bit instructions but is also as compact as possible. Most instructions are only 1 byte long with an implicit operand, a few have an operand encoded in a second byte. This results in very short programs that are tailored to the specified memory size.

A major disadvantage of the architecture was that conditional jumps could only be performed absolutely within a 256-byte page. In the case of program extensions, this led to readjustment of subsequent conditional jumps by adding direct long jumps to overcome the 256-byte page limit, which subsequently led to further code shifts with corrections. Several interventions in the assembler code and subsequent assemblies were the result. In the following MCS-51, this disadvantage was eliminated in that the conditional jumps could be carried out relatively ± 127 bytes to the jump instruction and were not bound to page boundaries.

Common features of all MCS-48 components:

• 8-bit processor core
• min. 64 bytes internal RAM
• optional external RAM and ROM
• Interval timer
• 2 interrupt sources

variants

View of the 8749H

MCS-48 variants
Type	ROM internal	RAM internal	comment
8020	1024	64	Mask-programmed low-cost CPU: no interrupts, no external program memory, reduced 8048 instruction set, 20 connections, 13 inputs / outputs
8021	1024	64	Mask-programmed low-cost CPU: no interrupts, no external program memory, stripped-down 8048 instruction set, 28 connections, 21 inputs / outputs
8022	2048	64	Mask-programmed low-cost CPU: A / D converter , voltage comparator inputs, no external program memory, stripped-down 8048 instruction set
8035	-	64	ROM-less version of the 8048, program in an external module
8039	-	128	ROM-less version of the 8049, program in an external module
8040	-	256	ROM-less version of the 8050, program in an external module
8048	1024	64	first microcontroller from Intel, founded the MCS-48 family
8049	2048	128	Further development of the 8048 with larger data and program memory
8050	4096	256	Further development of the 8049 with larger data and program memory
8648	1024	64	one-time programmable 8048, Factory OTP
8748	1024	64	reprogrammable 8048, EPROM instead of ROM
8749	2048	128	reprogrammable 8049, EPROM instead of ROM
87P50	-	256	Piggyback (piggyback) version with a socket for a 2716- EPROM (2 KB ) in the chip housing

View of the 8741

UPI-41 variants
Type	ROM internal	RAM internal	comment
8041	1024	64	slave processor derived from the 8048 with asynchronous data register for communication with a master processor (e.g. 8048/49/50)
8042	2048	128	slave processor derived from the 8049 with asynchronous data register for communication with a master processor (e.g. 8048/49/50)
8641	1024	64	one-time programmable 8041, Factory OTP
8741	1024	64	reprogrammable 8041, EPROM instead of ROM
8742	2048	128	reprogrammable 8042, EPROM instead of ROM
8271			Programmable floppy disk control module (permanently programmed interface module based on 8041)
8273			Programmable HDLC / SDLC control module (fixed-programmed interface module based on 8041)
8278			Programmable keyboard interface module (permanently programmed interface module based on 8041)
8292			IEC control module (fixed-programmed interface module based on 8041)
8294			Data encryption module (fixed-programmed interface module based on 8041)
8295			Control module for dot matrix printer (permanently programmed interface module based on 8041)

Known devices with MCS-48 components

• Philips G7000 , game console (1978), as the main processor
• Sinclair QL , Home Computer (1984), as coprocessor for peripherals
• IMSAI 8080 , Computer (1979), for querying the control panel
• Nintendo Donkey Kong , slot machine (8035-Clone MB8884 as sound processor)
• Kosmos CP1 , learning computer
• Entex Adventure Vision , game console (1982)
• Engine control unit Digijet VW T3 (2.1 liter injection engine code letter: DJ)
• Roland CR-78 , drum computer (1978), works with an 8048
• Roland Jupiter-4 , synthesizer (1978), works with two 8048 for parameter control and keyboard query
• Roland ProMars , Synthesizer (1979), works with two 8048 for parameter control and keyboard query
• Korg Poly-61 , Synthesizer (1982), works with two 8049 for parameter control and keyboard query
• Korg Polysix , Synthesizer (1981), works with an 8048 for parameter control and an 8049 for keyboard query
• Sequential Circuits Pro One, Synthesizer (1981), works with an 8021, u. a. for the sequencer

literature

MCS-48

• J. Koch (arr.): The MCS-48 Microcomputer Family, Features and Applications , Philips / Valvo, 1980, ISBN 3-87095-253-9 .
• J. Koch (arr.): The microcomputer family MCS-48, instruction set , Philips / Valvo, 1979, ISBN 3-8709-250-4 .
• Horst Pelka: The one-chip microcomputer , Franzis-Verlag, Munich 1981, 141 pages, ISBN 3-7723-6831-X .
• Microcomputer SAB 8048/8049 command list , ed. from Siemens AG, Components Division, Balanstrasse 73, 8000 Munich 80 (order no. B / 2516).
• Helmut Steffen: Control / process data processing in technology lessons, functional models with the INTEL single-chip computer 8048 , Ferd. Dümmler Verlag, Bonn 1995, 103 pages, ISBN 3-427-53411-1 .

• MCS-48 ™ Single Component Microcomputer , Applications Seminar Notebook, 1978, Intel Corporation.
• MCS-48 ™ MICROCOMPUTER USER'S MANUAL (PDF; 7.2 MB), 1978, Intel Corporation.
• Lionel Smith, Cecil Moore: Serial I / O and Math Utilities for the 8049 Microcomputer , Application Note AP-49, January 1979, Intel Corporation.
• A High-Speed ​​Emulator for Intel MCS-48 ™ Microcomputers , Application Note AP-55A, August 1979, Intel Corporation.
• Phil Dahm, Stuart Rosenberg: Intel MCS-48 ™ and UPI-41A ™ Microcontrollers , Reliability Report RR-25, December 1979, Intel Corporation.
• Microcontroller Handbook , Intel 1984, Order number 210918-002.
• 8-Bit Embedded Controllers , Intel 1991, Order number 270645-003.

UPI-41

• UPI-41A User's Manual , Intel 1980, Order number 9800504-02 Rev. B.
• Microprocessor Peripherals UPI-41A / 41AH / 42 / 42AH User's Manual (PDF; 718 kB), October 1993, Order number 231318-006, Intel Corporation.
• Johan Beaston, Jim Kahn: An 8741A / 8041A Digital Cassette Controller , Application Note AP-90, May 1980, Intel Corporation.

Individual evidence

1. ↑ ^{a b c} Intel's CPU family trees ( Memento from March 14, 2011 in the Internet Archive )
2. ↑ MCS-48 ™ MICROCOMPUTER USER'S MANUAL ( Memento of the original from July 21, 2011 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 7.2 MB), 1978, Intel Corporation. 
3. ↑ Chemnitz University of Technology: The AT motherboard ( Memento of the original from January 6, 2012 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. . 
4. ↑ Data sheet (pdf) ( Memento of the original from May 15, 2016) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Philips MAB8400 family. 
5. ↑ 8021 Single-Component 8-Bit Microcontroller ( "Intel Fair Applications Handbook" )
6. ↑ 8022 Single-Component 8-Bit Microcontroller With On Chip A / D Converter ( "Intel Fair Applications Handbook" )
7. ↑ ^{a b c} 8048/8748/8035 Single-Component 8-Bit Microcontroller ( "Intel Fair Applications Handbook" )
8. ↑ ^{a b} New High Performance 8049/8039 / 8039-6 Single-Component 8-Bit Microcontroller ( "Intel Fair Applications Handbook" )
9. ↑ ^{a b c} P8748H / P8749H / 8048AH / 8035AHL / 8049AH / 8039AHL / 8050AH / 8040AHL HMOS Single-Component 8-Bit Microcontroller ( "Intel Fair Applications Handbook" )
10. ↑ ^{a b} 8041AH / 8041AH-2 / 8641A / 8741A Universal Peripheral Interface 8-Bit Microcontroller ( "Intel Fair Applications Handbook" )
11. ↑ UPI-41AH / 42AH Universal Peripheral Interface 8-Bit Slave Microcontroller ( "Intel Fair Applications Handbook" )
12. ↑ 8741A UNIVERSAL PERIPHERAL INTERFACE 8-BIT MICROCOMPUTER (PDF; 214 kB), October 1989, Order number 290241-001, Intel Corporation ( "Intel Fair Applications Handbook" )
13. ↑ 8742 UNIVERSAL PERIPHERAL INTERFACE 8-BIT SLAVE MICROCONTROLLER (PDF; 216 kB), November 1991, Order number 290256-001, Intel Corporation ( "Intel Fair Applications Handbook" )

Web links

Commons : MCS-48  - collection of pictures, videos and audio files

• Grokking the MCS-48 System (PDF; 487 kB)