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54-501: The S1C6x series is a microcontroller families introduced by Epson . It is a 4-bit architecture. This Series includes S1C60 and S1C63 families. S1C60 is low end low power version. S1C63 is high end version. This family is used in many applications as it contains specialized peripherals such as LCD driver, dot-matrix driver, FSK demodulator, R/F converter ... etc. The S1C6x series is a CISC Harvard architecture with 12-bit instructions with an 8.192 word instruction space. It uses

108-741: A digital signal processor (DSP), with higher clock speeds and power consumption. The first multi-chip microprocessors, the Four-Phase Systems AL1 in 1969 and the Garrett AiResearch MP944 in 1970, were developed with multiple MOS LSI chips. The first single-chip microprocessor was the Intel 4004 , released on a single MOS LSI chip in 1971. It was developed by Federico Faggin , using his silicon-gate MOS technology, along with Intel engineers Marcian Hoff and Stan Mazor , and Busicom engineer Masatoshi Shima . It

162-480: A personal computer , and may lack human interaction devices of any kind. Microcontrollers must provide real-time (predictable, though not necessarily fast) response to events in the embedded system they are controlling. When certain events occur, an interrupt system can signal the processor to suspend processing the current instruction sequence and to begin an interrupt service routine (ISR, or "interrupt handler") which will perform any processing required based on

216-538: A "window" on the top of the device through which program memory can be erased by ultraviolet light, ready for reprogramming after a programming ("burn") and test cycle. Since 1998, EPROM versions are rare and have been replaced by EEPROM and flash, which are easier to use (can be erased electronically) and cheaper to manufacture. Other versions may be available where the ROM is accessed as an external device rather than as internal memory, however these are becoming rare due to

270-509: A 4-bit word for either a binary format or as a BCD digit and has 16 memory mapped registers in register window together with two accumulators , two 12-bit pointers and a stack pointer for use in subroutines . Most of the instructions operate on either two registers or a register and an immediate value, but the S1C6X series also has some memory-memory and memory-immediate instructions. Microcontroller In modern terminology,

324-488: A Harvard architecture is used, instruction words for the processor may be a different bit size than the length of internal memory and registers; for example: 12-bit instructions used with 8-bit data registers. The decision of which peripheral to integrate is often difficult. The microcontroller vendors often trade operating frequencies and system design flexibility against time-to-market requirements from their customers and overall lower system cost. Manufacturers have to balance

378-424: A device. So the analog-to-digital converter is used to convert the incoming data into a form that the processor can recognize. A less common feature on some microcontrollers is a digital-to-analog converter (DAC) that allows the processor to output analog signals or voltage levels. In addition to the converters, many embedded microprocessors include a variety of timers as well. One of the most common types of timers

432-520: A fork, CircuitPython , has looked to move hardware dependencies to libraries and have the language adhere to a more CPython standard. Interpreter firmware is also available for some microcontrollers. For example, BASIC on the early microcontroller Intel 8052 ; BASIC and FORTH on the Zilog Z8 as well as some modern devices. Typically these interpreters support interactive programming . Intel 4040 The Intel 4040 (" forty-forty ")

486-843: A general-purpose processor might require several instructions to test a bit in a register and branch if the bit is set, where a microcontroller could have a single instruction to provide that commonly required function. Microcontrollers historically have not had math coprocessors , so floating-point arithmetic has been performed by software. However, some recent designs do include FPUs and DSP-optimized features. An example would be Microchip's PIC32 MIPS-based line. Microcontrollers were originally programmed only in assembly language , but various high-level programming languages , such as C , Python and JavaScript , are now also in common use to target microcontrollers and embedded systems . Compilers for general-purpose languages will typically have some restrictions as well as enhancements to better support

540-425: A microcontroller from a low-power sleep state where the processor is halted until required to do something by a peripheral event. Typically microcontroller programs must fit in the available on-chip memory, since it would be costly to provide a system with external, expandable memory. Compilers and assemblers are used to convert both high-level and assembly language code into a compact machine code for storage in

594-551: A microcontroller is similar to, but less sophisticated than, a system on a chip (SoC). A SoC may include a microcontroller as one of its components but usually integrates it with advanced peripherals like a graphics processing unit (GPU), a Wi-Fi module, or one or more coprocessors . Microcontrollers are used in automatically controlled products and devices, such as automobile engine control systems, implantable medical devices, remote controls, office machines, appliances, power tools, toys, and other embedded systems . By reducing

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648-445: A new "bank 1", the original sixteen registers retroactively becoming "bank 0". The idea was that programmers would attempt to place their critical data in the first eight registers of bank 0. When an interrupt was received, the handler code would call an instruction to swap banks, which would cause bank 1's registers to override bank 0's registers 0 through 7. The handler code would then use these eight registers for any local data, leaving

702-766: A self-contained system with a processor, memory and peripherals and can be used as an embedded system . The majority of microcontrollers in use today are embedded in other machinery, such as automobiles, telephones, appliances, and peripherals for computer systems. While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system , and low software complexity. Typical input and output devices include switches, relays , solenoids , LED 's, small or custom liquid-crystal displays , radio frequency devices, and sensors for data such as temperature, humidity, light level etc. Embedded systems usually have no keyboard, screen, disks, printers, or other recognizable I/O devices of

756-408: A single 8-digit binary coded decimal value, the data format used by calculators. It also had four 12-bit registers for holding addresses, the top-most was the program counter and the next three operated as a push-down stack for subroutine calls. To reduce pin count to only 16, the original 4004 had only four data pins, multiplexed for both data and addresses. Additional pins indicated whether

810-574: A smaller and cheaper circuit board, and reduces the labor required to assemble and test the circuit board, in addition to tending to decrease the defect rate for the finished assembly. A microcontroller is a single integrated circuit , commonly with the following features: This integration drastically reduces the number of chips and the amount of wiring and circuit board space that would be needed to produce equivalent systems using separate chips. Furthermore, on low pin count devices in particular, each pin may interface to several internal peripherals, with

864-421: Is the programmable interval timer (PIT). A PIT may either count down from some value to zero, or up to the capacity of the count register, overflowing to zero. Once it reaches zero, it sends an interrupt to the processor indicating that it has finished counting. This is useful for devices such as thermostats, which periodically test the temperature around them to see if they need to turn the air conditioner on/off,

918-441: Is the second 4-bit microprocessor designed and manufactured by Intel . Introduced in 1974 as a successor to the Intel 4004 , the 4040 was produced with a 10 μm process and includes silicon gate enhancement-load PMOS logic technology. The 4040 contained 3,000 transistors and could execute approximately 62,000 instructions per second . General performance, bus layout and arithmetic logic unit (ALU) were identical to

972-401: The Intel 8048 , with commercial parts first shipping in 1977. It combined RAM and ROM on the same chip with a microprocessor. Among numerous applications, this chip would eventually find its way into over one billion PC keyboards. At that time Intel's President, Luke J. Valenter, stated that the microcontroller was one of the most successful products in the company's history, and he expanded

1026-425: The "ROM space" using RAM chips, there were no instructions able to write to that area of memory, and no instructions able to read program code from RAM space. The idea was that systems would supply the system program on ROM, and small amounts of RAM would be used only for data, if at all. In typical use, the internal "index registers" would be used for storage during calculations, with the 16 4-bit registers able to hold

1080-771: The "world's smallest computer" was announced by the University of Michigan . The device is a " 0.04  mm 16  nW wireless and batteryless sensor system with integrated Cortex-M0+ processor and optical communication for cellular temperature measurement." It "measures just 0.3 mm to a side—dwarfed by a grain of rice. [...] In addition to the RAM and photovoltaics , the new computing devices have processors and wireless transmitters and receivers . Because they are too small to have conventional radio antennae, they receive and transmit data with visible light. A base station provides light for power and programming, and it receives

1134-414: The 4004. The main improvement was to use a larger 24-pin dual inline package , giving it 8 more pins than the 16-pin 4004. Two of these were used to implement interrupts , which were lacking in the 4004 and considered a major oversight. Two more implemented a halt/stop system, which put the processor into a low-power mode and also allowed for single-step operation that made debugging much easier. Another pin

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1188-572: The 6501 and 6502 . Their chief aim was to reduce this cost barrier but these microprocessors still required external support, memory, and peripheral chips which kept the total system cost in the hundreds of dollars. One book credits TI engineers Gary Boone and Michael Cochran with the successful creation of the first microcontroller in 1971. The result of their work was the TMS 1000 , which became commercially available in 1974. It combined read-only memory, read/write memory, processor and clock on one chip and

1242-650: The 8-bit segment has dominated the MCU market [..] 16-bit microcontrollers became the largest volume MCU category in 2011, overtaking 8-bit devices for the first time that year [..] IC Insights believes the makeup of the MCU market will undergo substantial changes in the next five years with 32-bit devices steadily grabbing a greater share of sales and unit volumes. By 2017, 32-bit MCUs are expected to account for 55% of microcontroller sales [..] In terms of unit volumes, 32-bit MCUs are expected account for 38% of microcontroller shipments in 2017, while 16-bit devices will represent 34% of

1296-743: The OTP versions, which could be made in lower-cost opaque plastic packages. For the erasable variants, quartz was required, instead of less expensive glass, for its transparency to ultraviolet light—to which glass is largely opaque—but the main cost differentiator was the ceramic package itself. In 1993, the introduction of EEPROM memory allowed microcontrollers (beginning with the Microchip PIC16C84 ) to be electrically erased quickly without an expensive package as required for EPROM , allowing both rapid prototyping, and in-system programming . (EEPROM technology had been available prior to this time, but

1350-417: The ROM chips used with the 4004 and 4040 used these lines like chip select pins, and thus the two lines could only support two banks. The 4004 lacked interrupts , a serious limitation. The 4040 added a new input pin for calling an interrupt, as well an output pin to indicate the interrupt signal had been noticed and was being acted on. As interrupts also need to save a return address, the stack register file

1404-422: The address was in ROM or one of several "banks" of RAM. As addresses were 12 bits long, expressing an address took three cycles along with the subsequent read or write, and external circuitry had to latch each 4 bit part of the address between cycles. Instructions were 8 bits, so loading the next instruction required many cycles, which led to the slow performance in spite of what was a relatively fast cycle time for

1458-1035: The cheapest 8-bit microcontrollers being available for under US$ 0.03 in 2018, and some 32-bit microcontrollers around US$ 1 for similar quantities. In 2012, following a global crisis—a worst ever annual sales decline and recovery and average sales price year-over-year plunging 17%—the biggest reduction since the 1980s—the average price for a microcontroller was US$ 0.88 ( US$ 0.69 for 4-/8-bit, US$ 0.59 for 16-bit, US$ 1.76 for 32-bit). In 2012, worldwide sales of 8-bit microcontrollers were around US$ 4 billion , while 4-bit microcontrollers also saw significant sales. In 2015, 8-bit microcontrollers could be bought for US$ 0.311 (1,000 units), 16-bit for US$ 0.385 (1,000 units), and 32-bit for US$ 0.378 (1,000 units, but at US$ 0.35 for 5,000). In 2018, 8-bit microcontrollers could be bought for US$ 0.03 , 16-bit for US$ 0.393 (1,000 units, but at US$ 0.563 for 100 or US$ 0.349 for full reel of 2,000), and 32-bit for US$ 0.503 (1,000 units, but at US$ 0.466 for 5,000). In 2018,

1512-469: The data." The device is 1 ⁄ 10 th the size of IBM's previously claimed world-record-sized computer from months back in March 2018, which is "smaller than a grain of salt", has a million transistors, costs less than $ 0.10 to manufacture, and, combined with blockchain technology, is intended for logistics and "crypto-anchors"— digital fingerprint applications. A microcontroller can be considered

1566-467: The earlier EEPROM was more expensive and less durable, making it unsuitable for low-cost mass-produced microcontrollers.) The same year, Atmel introduced the first microcontroller using Flash memory , a special type of EEPROM. Other companies rapidly followed suit, with both memory types. Nowadays microcontrollers are cheap and readily available for hobbyists, with large online communities around certain processors. In 2002, about 55% of all CPUs sold in

1620-418: The era. The 4040 was essentially an expansion of the 4004, with additional pins, more registers and new instructions to take advantage of both. The 4004 had a single ROM pin, whereas the 4040 added another ROM pin to allow two banks of ROM. This effectively increased the ROM address from 12 to 13 bits, or 8 kB. Unlike later designs where the two lines could be binary encoded and thus support four banks,

1674-806: The heater on/off, etc. A dedicated pulse-width modulation (PWM) block makes it possible for the CPU to control power converters , resistive loads, motors , etc., without using many CPU resources in tight timer loops . A universal asynchronous receiver/transmitter (UART) block makes it possible to receive and transmit data over a serial line with very little load on the CPU. Dedicated on-chip hardware also often includes capabilities to communicate with other devices (chips) in digital formats such as Inter-Integrated Circuit ( I²C ), Serial Peripheral Interface ( SPI ), Universal Serial Bus ( USB ), and Ethernet . Microcontrollers may not implement an external address or data bus as they integrate RAM and non-volatile memory on

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1728-529: The latter, sometimes the designation OTP was used, standing for "one-time programmable". In an OTP microcontroller, the PROM was usually of identical type as the EPROM, but the chip package had no quartz window; because there was no way to expose the EPROM to ultraviolet light, it could not be erased. Because the erasable versions required ceramic packages with quartz windows, they were significantly more expensive than

1782-417: The low-priced microcontrollers above from 2015 were all more expensive (with inflation calculated between 2018 and 2015 prices for those specific units) at: the 8-bit microcontroller could be bought for US$ 0.319 (1,000 units) or 2.6% higher, the 16-bit one for US$ 0.464 (1,000 units) or 21% higher, and the 32-bit one for US$ 0.503 (1,000 units, but at US$ 0.466 for 5,000) or 33% higher. On 21 June 2018,

1836-427: The microcontroller division's budget by over 25%. Most microcontrollers at this time had concurrent variants. One had EPROM program memory, with a transparent quartz window in the lid of the package to allow it to be erased by exposure to ultraviolet light. These erasable chips were often used for prototyping. The other variant was either a mask-programmed ROM or a PROM variant which was only programmable once. For

1890-432: The microcontroller's memory. Depending on the device, the program memory may be permanent, read-only memory that can only be programmed at the factory, or it may be field-alterable flash or erasable read-only memory. Manufacturers have often produced special versions of their microcontrollers in order to help the hardware and software development of the target system. Originally these included EPROM versions that have

1944-474: The need to minimize the chip size against additional functionality. Microcontroller architectures vary widely. Some designs include general-purpose microprocessor cores, with one or more ROM, RAM, or I/O functions integrated onto the package. Other designs are purpose-built for control applications. A microcontroller instruction set usually has many instructions intended for bit manipulation (bit-wise operations) to make control programs more compact. For example,

1998-409: The new logical AND and OR operators, the instruction set added 14 new instructions, bringing the total to 60. Federico Faggin proposed the project, formulated the architecture and led the design. The detailed design was done by Tom Innes . The 4040 was first used in a microcomputer in Intel 's Intellec 4 Mod 40 development system, released in early 1975. According to Byte magazine,

2052-441: The original values untouched. When the handler completed, it simply swapped bank 0 back in. This reduced the switching time to a single instruction, greatly improving interrupt response times. Another addition was the input stop pin, and the associated output stop acknowledge. These could be used to stop the processor while the system performed input/output or other non-CPU tasks, but was more widely used for debugging by allowing

2106-435: The output state, GPIO pins can drive external devices such as LEDs or motors, often indirectly, through external power electronics. Many embedded systems need to read sensors that produce analog signals. This is the purpose of the analog-to-digital converter (ADC). Since processors are built to interpret and process digital data, i.e. 1s and 0s, they are not able to do anything with the analog signals that may be sent to it by

2160-596: The physical world as edge devices . Some microcontrollers may use four-bit words and operate at frequencies as low as 4 kHz for low power consumption (single-digit milliwatts or microwatts). They generally have the ability to retain functionality while waiting for an event such as a button press or other interrupt ; power consumption while sleeping (CPU clock and most peripherals off) may be just nanowatts, making many of them well suited for long lasting battery applications. Other microcontrollers may serve performance-critical roles, where they may need to act more like

2214-409: The pin function selected by software. This allows a part to be used in a wider variety of applications than if pins had dedicated functions. Microcontrollers have proved to be highly popular in embedded systems since their introduction in the 1970s. Some microcontrollers use a Harvard architecture : separate memory buses for instructions and data, allowing accesses to take place concurrently. Where

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2268-427: The processor to be single-stepped. When the processor was in stopped mode, most of the chip hardware put into a low-drain, high-impedance condition, reducing power use. The machine cycle clocks were kept running for the benefit of external devices, including any interrupt controllers needed to wake the chip back up, which relied on these controllers staying in sync. To take advantage of these new features, and to support

2322-461: The same chip as the CPU. Using fewer pins, the chip can be placed in a much smaller, cheaper package. Integrating the memory and other peripherals on a single chip and testing them as a unit increases the cost of that chip, but often results in decreased net cost of the embedded system as a whole. Even if the cost of a CPU that has integrated peripherals is slightly more than the cost of a CPU and external peripherals, having fewer chips typically allows

2376-514: The size and cost compared to a design that uses a separate microprocessor , memory, and input/output devices, microcontrollers make digital control of more devices and processes practical. Mixed-signal microcontrollers are common, integrating analog components needed to control non-digital electronic systems. In the context of the Internet of Things , microcontrollers are an economical and popular means of data collection , sensing and actuating

2430-434: The source of the interrupt, before returning to the original instruction sequence. Possible interrupt sources are device-dependent and often include events such as an internal timer overflow, completing an analog-to-digital conversion, a logic-level change on an input such as from a button being pressed, and data received on a communication link. Where power consumption is important as in battery devices, interrupts may also wake

2484-778: The time of manufacture can be economical. These " mask-programmed " parts have the program laid down in the same way as the logic of the chip, at the same time. A customized microcontroller incorporates a block of digital logic that can be personalized for additional processing capability, peripherals and interfaces that are adapted to the requirements of the application. One example is the AT91CAP from Atmel . Microcontrollers usually contain from several to dozens of general purpose input/output pins ( GPIO ). GPIO pins are software configurable to either an input or an output state. When GPIO pins are configured to an input state, they are often used to read sensors or external signals. Configured to

2538-536: The total, and 4-/8-bit designs are forecast to be 28% of units sold that year. The 32-bit MCU market is expected to grow rapidly due to increasing demand for higher levels of precision in embedded-processing systems and the growth in connectivity using the Internet. [..] In the next few years, complex 32-bit MCUs are expected to account for over 25% of the processing power in vehicles. Cost to manufacture can be under US$ 0.10 per unit. Cost has plummeted over time, with

2592-576: The unique characteristics of microcontrollers. Some microcontrollers have environments to aid developing certain types of applications. Microcontroller vendors often make tools freely available to make it easier to adopt their hardware. Microcontrollers with specialty hardware may require their own non-standard dialects of C, such as SDCC for the 8051 , which prevent using standard tools (such as code libraries or static analysis tools) even for code unrelated to hardware features. Interpreters may also contain nonstandard features, such as MicroPython , although

2646-438: The widespread availability of cheap microcontroller programmers. The use of field-programmable devices on a microcontroller may allow field update of the firmware or permit late factory revisions to products that have been assembled but not yet shipped. Programmable memory also reduces the lead time required for deployment of a new product. Where hundreds of thousands of identical devices are required, using parts programmed at

2700-621: The world were 8-bit microcontrollers and microprocessors. Over two billion 8-bit microcontrollers were sold in 1997, and according to Semico, over four billion 8-bit microcontrollers were sold in 2006. More recently, Semico has claimed the MCU market grew 36.5% in 2010 and 12% in 2011. A typical home in a developed country is likely to have only four general-purpose microprocessors but around three dozen microcontrollers. A typical mid-range automobile has about 30 microcontrollers. They can also be found in many electrical devices such as washing machines, microwave ovens, and telephones. Historically,

2754-438: Was expanded to seven entries, up from three. Interrupt handler code normally starts by saving out values in the registers to allow the interrupt code to use them, and then at the end it copies the values back from memory so that the processor returns to its original pre-interrupt state. With the multi-cycle memory access of the design, this would have been extremely slow. To address this, eight additional registers were added in

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2808-442: Was followed by the 4-bit Intel 4040 , the 8-bit Intel 8008 , and the 8-bit Intel 8080 . All of these processors required several external chips to implement a working system, including memory and peripheral interface chips. As a result, the total system cost was several hundred (1970s US) dollars, making it impossible to economically computerize small appliances. MOS Technology introduced its sub-$ 100 microprocessors in 1975,

2862-436: Was targeted at embedded systems. During the early-to-mid-1970s, Japanese electronics manufacturers began producing microcontrollers for automobiles, including 4-bit MCUs for in-car entertainment , automatic wipers, electronic locks, and dashboard, and 8-bit MCUs for engine control. Partly in response to the existence of the single-chip TMS 1000, Intel developed a computer system on a chip optimized for control applications,

2916-626: Was used to bank select a second read only memory (ROM), doubling the amount of ROM the processor could address compared to the 4004. To make use of these new pins, the instruction set was expanded, increasing it to 60 instructions from the original 46. Additionally, the internal register file and pushdown stack were expanded to support rapid interrupt processing. The 4004 was designed to be used in an electronic calculator and many of its design notes are related to this role. For instance, program code can only be read from an area dedicated to read only memory , not RAM. Although one could implement

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