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Intel Microcontroller Families
MCS-48 MCS-41 MCS-51 MCS-96


Since 1975 Intel has been producing many different types of microcontrollers. In general each MCU that Intel has made falls into one of the below families. The families differ mostly in instruction sets and architecture. Within each family there are many different CPUs. While each CPU may have the same core the feature set can vary a lot. Common differences within a single family are:

  • On-Board ROM size
  • On-Board RAM size
  • Reprogrammability
  • ADCs
  • Timers
  • And many other features

Microcontroller usually contain the programs they run on the chip themselves, or off the chip on a ROM.
Intel used several naming conventions to specify wether the chip had ROM or not. and wether it was programmable.

80xxx** ROMLESS
82xxx Predesigned Mask ROM (8242 keyboard controller)
83xxx Mask ROM
86xx OTP ROM
87Axx Automotive Grade

* 80 was used for ROM and ROMLESS versions of MCS41 48 and 51 before
Intel created a better nameing convention.

Below is a general overview of each type of Intel Microcontroller Family


Intel MCS-48 - Introduced 1976

The Intel 8048 microcontroller, Intel's first µC, was used in the Magnavox Odyssey² video game console (as a 100KHz 8021) and (in its 8042 variant) in the original IBM PC keyboard. The 8048 is probably the most prominent member of Intel's MCS-48 familiy of microcontrollers. It was inspired by, and is somewhat similar to, the Fairchild F8 microprocessor.

The MCS-48 has over 90 instructions with 90% of them being single byte.

The 8048 has a modified Harvard architecture, with internal or external program ROM and 64–256 bytes of internal (on-chip) RAM. The I/O is mapped into its own address space, separate from programs and data. Though the 8048 was eventually replaced by the very popular Intel 8051, even at the turn of the millennium it remains quite popular, due to its low cost, wide availability, memory efficient one-byte instruction set, and mature development tools. Because of this it is much used in high-volume consumer electronics devices such as TV sets, TV remotes, toys, and other
gadgets where cost-cutting is essential.

Device RAM (bytes) ROM Speed Timers Ports Picture
64 1024 100-400KHz 2 2x8, 1x4
128 2048 100-400KHz 2 3x8 Has an ADC
8035 64 - 11MHz    
8038 64 -     3x8  
8039 128 - 11MHz   3x8
8040 256 - 11MHz      
8048 64 1024 11MHz 2 3x8
8049 128 2048 11MHz 2 3x8
8050 256 4096 11MHz      
**2 pins are High Current Driving outputs

Intel MCS-41 - Introduced 1979

MCS-41 are slave controllers commonly used for keyboard control or other simple tasks such as ADC control.

The Intel UPI-41/42 is a general-purpose Universal Peripheral Interface that allows designers to grow their own customized solution for peripheral device control. It contains a low-cost microcomputer with 2K of program memory, 128 bytes of data memory, 8-bit timer/counter, and clock generator in a single 40-pin package. Interface registers are included to enable the UPI device to function as a peripheral controller in the
MCSÉ-48,MCS-51, MCS-80, MCS-85, 8088, 8086 and other 8-, 16-bit systems. The 8742 is software, pin, and architecturally compatible
with the 8741A. The 8742 doubles the on-chip memory space to allow for additional features and performance to be incorporated in upgraded 8741A designs. For new designs, the additional memory and performance of the 8742 extends the UPI concept to more complex motor control
tasks, 80-column printers and process control applications as examples.

The UPI-41 has over 90 instructions with 70% of them being single byte.

Device RAM (bytes) ROM Speed ADCs Timers Ports Picture
8041 128 1024 6MHz   2 3x8
8042 256 2048 12.5MHz   2  

Intel MCS-51 - Introduced 1980

The MCS-51 Family includes 2 timers and 4 ports as well as 128bytes or more of on board RAM. The 51 is one of the most popular MCUs on the market. It is now being made in speeds of up to 100MHz by SiLabs, while Intel continues to make them up to 33MHz.

The standard MCS-51 instruction set has 111 instructions with 64 of them executing in a single cycle. They can support up to 64k of external prgram, and 54k of external memory space.

The MCS-51 family is now made by dozens of companies, with many different features. Below is but a small list of these companies:
All told there areover 1000 versions of the 8051 core.
Atmel 89x
Infineon C500
And many more...

The Intel 8xC251TB/TQ and 8xC251SA/SB/SP/SQ are based on the new high performance MCS® 251 micro-controller architecture. Being members of the MCS 251 microcontroller family, the 8xC251TB/TQ and 8xC251SA/SB/SP/SQ have the same advanced register based CPU architecture and a pipelined instruction execution unit. They use the powerful MCS 251 microcontroller instruction set, with many enhanced 8, 16 and 32-bit instructions available. The new microcontrollers are also specially designed to execute C code efficiently. Most importantly, the 8xC251TB/TQ and 8xC251SA/SB/SP/SQ are binary code and pin compatible with the existing MCS 51 microcontrollers. They represent the easiest way to upgrade performance of existing MCS 51 microcontroller applications, delivering up to 15 times the performance.

Device RAM (bytes) ROM Speed Timers Ports Picture
8031 128 - 12MHz 2 4x8
8032 256 - 12MHz 2 4x8
8044* 192 4096 12MHz 2 4x8
8051 128 4096 12MHz 2 4x8
8052 256 8192 24MHz 2 4x8
8054 256 16K 24MHz 3 4x8
8058 256 32K 33MHz 3 4x8  
8x251SA 1k 8k 16MHz 3 32  
8x251SB 1k 16k 16MHz 3 32  
8x251SP 512 8k 16MHz 3 32  
8x251SQ 512 16k 16MHz 3 32  
8x251TB 1K 16k 24MHz 3 32
8251TQ 512 - 24MHz 3 32  
USB Equipped MCS-251            
80930Ax 512-1024 - 12MHz      
83930Ax 512-1024 8-16K 12MHz      

* 8044 Includes a high-speed serial interface.

Intel MCS-96 - Introduced 1982

Intel® MCS 96 microcontroller family of products are popular for 16-bit embedded microcontrollers. The 8XC196 products are found in a variety of embedded applications. The high-performance register to register architecture is well suited for complex real-time control applications such as hard disk drives, modems, printers, pattern recognition and motor control. Our broad portfolio of 8XC196 microcontroller products has been designed to meet your varying peripheral, memory size, addressability and performance requirements.

The 8XC196 family shares a common core architecture which is register based. The MCS 96 microcontroller register architecture eliminates the accumulator bottleneck and enables fast context switching. All devices have bit, byte, word and some 32-bit operations. The table below summarizes the capture and generation of high speed signals on the HSIO and EPA.

The MCS-96, like the MCS-51 is a MCU that is still being made, after 25 years of production there is still no plans to terminate it, just add more features, and get the clock even higher.

Device RAM (bytes) ROM Speed ADCs Timers I/O Lines Picture
8095 232 - 12MHz 4 2 5x8
8395 232 8192 12MHz 4 2 5x8  
8096 232 - 12MHz - 2 5x8  
8396 232 8192 12MHz - 2 5x8  
8097 232 - 12MHz 8 2 5x8  
8397 232 8192   8 2 5x8  
Next Generation              
87C196KR 488/256 16K 16MHz 8 2 56  
87C196KQ 360/128 12K 16MHz 8 2 56  
87C196JV 1.5K/512 48K 16MHz 6 2 41  
87C196JT 1K/512 32K 16MHz 6 2 41  
87C196JR 488/256 16K 16MHz 6 2 41  
87C196JQ 360/128 12K 16MHz 6 2 41  
87C196LA 768 24K 20MHz 6 2    
87C196LB 768 24k 20MHz 6 2    
83C196LC 1K/512 32K 22MHz 6 2    
83C196LD 384 16K 22MHz 6 2    
High Speed I/O Family              
8x196KB 232 8k 16MHz 8 2 48
8x196KC 488 16k 20MHz 8 2 48
8x196KD 1000 32k 20MHz 8 2 48
Motor Control Family              
8x196MC 488 16k 16MHz 13 2 53  
8x196MD 488 16k 16MHz 14 2 64  
8x196MH 744 32k 16MHz 8 2 52  
EPA Famlily (Event processor array)              
87C196CA 1000 32k 16MHz 6 2 44  
87C196CB 1.5k 56k 16MHz 8 2 56  
87C196NP 1000 4k 14MHz 0 2 32  
87C196NT 1000 32k 20MHz 4 2 56  
87C196NU 1024 - 50MHz 0 2 32  
87C196EA 1000 - 40MHz 16 4 83  
MCS-296 (DSP Enhanced)              
80296SA 512 2k 50MHz 0 2 32  

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