What is the connection between MCU, ARM, MCU, DSP, FPGA, and embedded?

First of all, "embedded" is a concept, there is no accurate definition, and each book has its own definition. But the main idea is the same, that is, compared to the general system of the PC, the embedded system is a dedicated system, the structure is streamlined, and only the required parts are retained in the hardware and software, and the unnecessary parts are cut off. Therefore, embedded systems generally have the characteristics of portability, low power consumption, and single performance.

Then, MCU, DSP, and FPGA are all categories of embedded systems, and are tools used to achieve a certain purpose.

MCU, commonly known as "single-chip computer", after so many years of development, has long been more than just the 51 Princeton structure, and its performance has been greatly improved. Because the MCU must execute the program sequentially, it is suitable for control and is more widely used in industry. ARM is a company that specializes in designing MCUs. Due to advanced technology and proper strategy, the market share of MCUs in the past two years is huge. ARM's MCUs come in many varieties, from low-end M0 (small appliances) to high-end A8, A9 (mobile phones, tablet PCs) are very popular, so it is not ARM's MCU must be on the system, the key to see the application.

The DSP is called a digital signal processor. Its structure is different from that of the MCU, which speeds up the operation and highlights the computing power. Think of it as a super fast MCU. Low-end DSPs, such as the C2000 series, are mainly used in motor control, but TI seems to call it a DSC (Digital Signal Controller) between the MCU and the DSP. High-end DSPs, such as the C5000/C6000 series, are generally used for video image processing and communication devices that require a lot of computation.

The FPGA is called a field programmable logic array. It has no function in itself. It is like a piece of white paper. It wants to be completely designed by programmers. All its processes are hardware, including VHDL and Verilog HDL programming. , prepared generally called "logic".). If you have enough NB, you can turn it into an MCU or a DSP. Since the internal structures of the MCU and DSP are well designed, they can only be processed sequentially by software programming, while the FPGA can be processed in parallel and sequentially, so it is the fastest.

So why do MCUs, DSPs, and FPGAs exist at the same time? That's because the internal structure of the MCU and DSP is designed by IC designers. When the same function is completed, the power consumption and price are much lower than those of the FPGA. Moreover, the development of FPGA itself is more complicated, and the human and financial resources required to complete the same function are also more. Therefore, each of the three has its own strengths, each with its own use. However, there is already a convergence between the three. ARM's M4 series adds a streamlined DSP core. TI's DaVinci series is ARM+DSP structure. ALTERA and XINLIX's new FPGAs all include ARM. The core is inside. So the relationship between the three is more and more like the three circles of the three primary colors.

In a word, "You have me, I have you."

MCU: usually no operating system, for simple control, such as elevators, air conditioners, etc.

Dsp: For complex calculations, such as discrete cosine transform, fast Fourier transform, commonly used for image processing, used in devices such as digital cameras.

Arm: A British chip design company, but does not produce chips. Only sell intellectual property.

Fpga: Field programmable gate array, the circuit design completed by hardware description language (Verilog or VHDL), can be quickly burned to the FPGA for testing through simple synthesis and layout, which is the mainstream of modern IC design verification technology.

Embedded is relative to desktop computers. The system can be tailored and in various shapes. It may be limited in size, power consumption, cost, and real-time requirements, such as oscilloscopes, mobile phones, tablets, fully automatic washing machines, routers, digital cameras, these devices, although see the existence of the desktop, but has one or more embedded systems at work.

Different choices are provided depending on the functional complexity of the object system and the complexity of the computational processing. For a simple home appliance control embedded system, the use of a simple 8-bit microcontroller is sufficient, cheap and good, for mobile phones and game consoles, you must use 32-bit ARM and DSP chips. FPGA is a more hardware-oriented implementation.

So to learn to become a hardware engineer, start with a microcontroller, and then learn ARM and DSP.

The single-chip microcomputer can now be said to be overwhelming, and the variety is so wide that the developers are overwhelmed and the development is quite rapid. From the 80s of the last century, the four-bit 8-bit at that time has developed to various high-speed single-chip microcomputers.

Various manufacturers are also one after another in speed, memory, and function. At the same time, a large number of manufacturers with representative single-chip microcomputers emerged: Atmel, TI, ST, MicroChip, ARM... The domestic macro-crystal STC microcontroller is also a good one. point…

Here are the advantages and disadvantages between 51, MSP430, TMS, STM32, PIC, AVR, and STC microcontrollers.

51 single chip microcomputer

The most widely used 8-bit single-chip microcomputer is of course the most easy-to-learn microcontroller for beginners. It was first introduced by Intel. Due to its typical structure and centralized management of bus-specific registers, numerous logic bit operation functions and rich control-oriented functions. The instruction system, called the "classic" of a generation, laid the foundation for the development of other microcontrollers in the future.

The reason why 51 single-chip microcomputer has become a classic, has become the easy-to-use single-chip microcomputer has the following characteristics:

characteristic:

1. From internal hardware to software, there is a complete set of bit-wise operating system called bit processor. The processing object is not a word or a byte but a bit. Not only can some bits of some special function registers in the chip be processed, such as transfer, set, clear, test, etc., but also bit logic operations, its function is very complete, and it is easy to use.

2. At the same time, in the on-chip RAM area, a dual-function address range is specially opened, which is extremely flexible to use. This function undoubtedly provides great convenience to the user.

3. Multiplication and division instructions, which also bring convenience to programming. Many 8-bit MCUs do not have a multiply function. When multiplying, they have to be programmed with a subroutine call, which is very inconvenient.

Disadvantages: (although it is classic but the disadvantages are obvious)

1.AD, EEPROM and other functions need to be extended to increase the burden of hardware and software.

2. Although the I/O pin is easy to use, there is no output capability at high level, which is the biggest weakness of the 51 series MCU.

3. The running speed is too slow, especially the double data pointer. If it can be improved, it will bring great convenience to programming.

4. 51 protection ability is very poor, it is easy to burn out the chip

Application range:

It is widely used in teaching occasions and occasions where performance requirements are not high.

Most used devices: 8051, 80C51

MSP430 microcontroller

MSP430 series MCU is a 16-bit ultra-low power mixed-signal processor that Texas Instruments has introduced to the market in 1996. The biggest bright spot left by people is low power consumption and fast speed. Assembly language is very flexible. There are many addressing methods, few instructions, and easy to use. Mainly due to its practical application requirements, many analog circuits, digital circuits and microprocessors are integrated on one chip to provide a "single-chip" solution. Its rapid development and expanding application range mainly depend on the following characteristics...

characteristic:

1. Powerful processing capability, reduced instruction set (RISC) structure, rich addressing modes (7 source operand addressing, 4 destination operand addressing), 27 simple kernel instructions, and a large number of Analog instructions; a large number of registers and on-chip data memory can participate in a variety of operations; there are efficient table lookup processing instructions; a higher processing speed, the instruction cycle is 125 ns under 8MHz crystal drive. These features ensure that highly efficient source programs can be programmed

2. In terms of operation speed, 125ns instruction cycle can be realized under the driving of 8MHz crystal. 16-bit data width, 125ns instruction cycle, and a versatile hardware multiplier (multiply-accumulate) that enables some algorithms for digital signal processing (such as FFT)

3. In terms of ultra-low power consumption, the MSP430 microcontroller has ultra-low power consumption because it has its own unique features in reducing the power supply voltage of the chip and the flexible and controllable running clock. The power supply voltage is from 1.8 to 3.6V. Therefore, when the clock is running at 1MHz, the current of the chip will be around 200~400uA, and the minimum power consumption of the clock shutdown mode is only 0.1uA.

Disadvantages:

1. Personal feeling is not easy to get started, not suitable for beginners to get started, the information is relatively small, you can only go to the official website to find

2. The instruction space is large, because it is a 16-bit microcontroller, the program is in words, and some instructions actually occupy 6 bytes. Although the program is simple on the surface, it takes a lot of space compared to the pic microcontroller.

Application range:

More applications in industrial applications with low power consumption and ultra low power consumption

Most used devices: MSP430F series, MSP430G2 series, MSP430L09 series

TMS microcontroller

Here also mention the TMS series of microcontrollers, although not mainstream. The 8-bit CMOS microcontroller from TI offers a variety of memory modes and a variety of peripheral interface modes for complex real-time control applications. Although not as good as STM32, and not as aggressive as MSP430, TMS370C series MCU provides real-time system control with cost-effective integration by integrating advanced peripheral function modules and memory configurations of various chips. It is also implemented using high-performance silicon gate CMOS EPROM and EEPROM technology. Low operating power CMOS technology, wide operating temperature range, noise rejection, high performance and rich on-chip peripheral functions make the TMS370C family of microcontrollers a must for automotive electronics, industrial motor control, computer, communications and consumer applications. .

STM32 microcontroller

The STM32 series of single-chip microcomputers introduced by ST manufacturers, the industry's friends know that this is a series of high-performance single-chip microcontrollers, there should be no one, the function and its powerful. It is based on an ARM Cortex-M core specifically designed for embedded applications requiring high performance, low cost, low power, and first-class peripherals: 1μs dual 12-bit ADC, 4 Mbit/s UART, 18 Megabits per second SPI, etc., also has a good performance in terms of power consumption and integration. Of course, it is slightly inferior to the power consumption of MSP430, but this does not affect the degree of enthusiasm of engineers. Because of its simple structure and easy-to-use tools, it is well-known in the industry for its powerful functions... Its powerful features are mainly reflected in:

characteristic:

1. Kernel: ARM32 bit Cortex-M3CPU, maximum operating frequency 72MHz, 1.25DMIPS/MHz, single cycle multiplication and hardware division

2. Memory: 32-512KB Flash memory is integrated on-chip. 6-64KB SRAM memory

3. Clock, reset and power management: 2.0-3.6V power supply and I/O interface drive voltage. POR, PDR and programmable voltage detector (PVD). 4-16MHz crystal oscillator. Built-in factory-adjusted 8MHz RC oscillator circuit. Internal 40 kHz RC oscillator circuit. PLL for the CPU clock. 32kHz crystal with calibration for RTC

4. Debug mode: Serial Debug (SWD) and JTAG interface. Up to 112 fast I/O ports, up to 11 timers, up to 13 communication interfaces

Most used devices: STM32F103 series, STM32 L1 series, STM32W series

PIC microcontroller

PIC microcontroller series is a product of Microship, which is divided into three levels, namely basic level, intermediate level and advanced level. It is one of the fastest growing single-chip microcomputers in the market. The CPU adopts RISC structure, respectively 33, 35 The 58 instructions are a reduced instruction set and adopt Harvard dual bus structure. The running speed is fast. It can make program memory access and data memory access parallel processing. This instruction pipeline structure completes two parts in one cycle. One is to execute the instruction, the other is to take the next instruction from the program memory, so that it seems that each instruction only needs one cycle, which is one of the reasons for high-efficiency operation. In addition, the reason why PIC microcontroller becomes a very hot single-chip microcomputer Nothing more than the following characteristics:

Features:

1. It has the characteristics of low working voltage, low power consumption and strong driving ability. The I/O ports of the PIC series MCUs are bidirectional, and their output circuits are CMOS complementary push-pull output circuits. The I/O pin adds a direction register for setting the input or output state, which solves the state of the input and output when the 51 series I/O pin is high.

2. When set to 1, it is the input state, and regardless of whether the pin is high or low, it is in a high-impedance state; when it is set to 0, it is an output state, regardless of the level of the pin, it is low. The resistance state has a considerable driving capability, the low-level sink current reaches 25mA, and the high-level output current can reach 20mA. This is a big advantage over the 51 series.

3. It can directly drive the digital tube display and the external circuit is simple. Its A/D is 10 bits, which can meet the accuracy requirements. With online debugging and programming (ISP) capabilities.

Inadequacies:

The dedicated registers (SFRs) are not concentrated in a fixed address range (80 to FFH) like the 51 series, but are scattered in four address ranges. Only five dedicated registers PCL, STATUS, FSR, PCLATH, and INTCON appear simultaneously in four banks, but in the programming process, it is indispensable to deal with special registers, and the corresponding bank must be selected repeatedly, that is, the status register STATUS Bit 6 (RP1) and 5 (RP0) are set or cleared. The data transfer and logic operations basically have to be done through the working register W (equivalent to the 51 series accumulator A), and the 51 series can also be directly transferred between the registers, so the bottleneck phenomenon of the PIC microcontroller is better than the 51 series. Still serious, this friend in programming should have a deep understanding

Most used devices: PIC16F873, PIC16F877

AVR microcontroller

AVR MCU is a relatively novel MCU introduced by Atmel Corporation. Its remarkable features are high performance, high speed and low power consumption. It cancels the machine cycle and executes the pipeline operation with the clock cycle as the instruction cycle. AVR microcontroller instructions are in word units, and most of the instructions are single-cycle instructions. The single cycle can perform the function of this instruction and complete the reading of the next instruction. Usually the clock frequency is 4 to 8 MHz, so the shortest instruction execution time is 250 to 125 ns. AVR MCU can become a relatively hot MCU recently, the main features:

Features:

1. The AVR series does not have a structure similar to the accumulator A. It mainly implements the function of A through the R16 to R31 registers. In the AVR, there is no data pointer DPTR like the 51 series, but three 16-bit registers of X (composed of R26, R27), Y (composed of R28, R29), and Z (composed of R30 and R31). The function of the data pointer (equivalent to three sets of DPTR), but also can be used for post-increment or first-decrease operation. In the 51 series, all logic operations must be performed in A; while AVR can be used in any two. Between the registers, eliminating the need to toss back and forth in A, these are better than the 51 series

2. AVR's special registers are concentrated in the 00~3F address range. It is not necessary to select the bank before PIC, which is more convenient to use than PIC. The address range of the AVR's on-chip RAM is 0~00DF (AT90S2313) and 0060~025F (AT90S8515, AT90S8535). They occupy the address of the data space. These on-chip RAMs are only used to store data, usually not universal. The function of the register. When the program is complicated, the general-purpose registers R0 to R31 are not enough; and the 51 series of general-purpose registers are up to 128 (four times that of the AVR), and this is not the case when programming.

3. AVR's I/O pin is similar to PIC. It also has a direction register for controlling input or output. In the output state, the high-level output current is about 10mA, and the low-level sink current is 20mA. This is not as good as PIC, but it is better than the 51 series...

Disadvantages:

1. There is no bit operation, it is to control and judge the relevant register bits in bytes.

2. C language and 51 C language in the writing method is very different, which makes friends from the beginning of learning 51 microcontroller is not used to

3. A total of 32 general-purpose registers (R0 ~ R31), the first 16 registers (R0 ~ R15) can not directly deal with the immediate, so the versatility has decreased. In the 51 series, all of its general-purpose registers (addresses 00 to 7FH) can directly deal with immediate data, which is obviously better than the former.

Most used devices: ATUC64L3U, ATxmega64A1U, AT90S8515

STC microcontroller

Speaking of STC microcontrollers, some people will say that STC can also be considered mainstream, it is estimated to be sprayed ~ ~ we are based on it is a relatively good domestic microcontroller. STC MCU is a single-clock/machine cycle MCU produced by Macro-Crystal. It is said that STC MCU is a combination of 51 and AVR. Some people say that AVR is a substitute for MCU 51, but AVR MCU has great control in place control and C language. The difference. The STC MCU negotiates the advantages of 51 and AVR. Although the function is not as powerful as AVR, the functions that can be found in AVR are basically on STC. At the same time, STC is 51 core, which is based on 51 MCU. The engineers provided great convenience, saving the time to learn AVR, while also losing the various functions of AVR...

STC MCU is a new generation of 8051 MCU 51 high-speed, low-power, super anti-interference, the instruction code is fully compatible with the traditional 8051, but the speed is 8~12 times faster, and the internal MAX810 dedicated reset circuit is integrated. 4-channel PWM 8-channel high-speed 10-bit A, D conversion, for the motor motor supplier control, strong interference occasions, become a new series of single-chip microcomputer after 51 MCU...

characteristic:

1. Download and burn the program with the serial port is convenient and easy to use, has a lot of learning materials and videos, the most famous one belongs to the video of Teacher Du, and many friends who are interested in the microcontroller are getting started with this video. At the same time has a wide voltage: 5.5 ~ 3.8V, 2.4 ~ 3.8V, low power design: idle mode, power down mode (can be awakened by an external interrupt)

2. STC MCU has application programming, debugging is more convenient; with 10-bit AD, internal EEPROM, can work in 1T / machine cycle, the speed is 8~12 times of the traditional 51 MCU, the price is also cheaper

3.4 Channel Capture/Compare Unit, STC12C2052AD series is 2 channels, can also be used to implement 4 timers or 4 external interrupts, 2 hardware 16-bit timers, compatible with ordinary 8051 timers. 4 channels of PCA can also realize 4 timers, with hardware watchdog, high-speed SPI communication port, full-duplex asynchronous serial port, compatible with ordinary 8051 serial port, and also has advanced instruction set structure, compatible with ordinary 8051 instructions. set

PS: STC MCU function is not as powerful as AVR and STM32, and the price is not as cheap as 51 and ST32, but these are not important. The important thing is that this is a good MCU of domestic MCU. I hope that MCU can be all the way...

Most used devices: STC12C2052AD

Freescale microcontroller

Mainly for S08, S12 such microcontrollers, of course, Freescale microcontroller is far from this. The Freescale series of microcontrollers use Harvard architecture and pipelined instruction architecture, which demonstrates low cost and high performance in many fields. Its architecture saves a lot of time for product development. In addition, Freescale provides a variety of integrated modules and bus interfaces, which can be more flexible in different systems! The unique features of Freescale microcontrollers are as follows:

1. Full range: from low-end to high-end, from 8-bit to 32-bit full range, its 8-bit/32-bit pin-compatible QE128 can be directly ported from 8-bit to 32-bit, making up for the microcontroller industry 8/ Missing link in 32-bit compatible architecture

2. A variety of system clock modules: three modules, seven working modes. A variety of clock source input options, different mcu have different clock generation mechanisms, can be RC oscillator, external clock or crystal, or internal clock, most CPUs have the above three modules! Can run in FEI, FEE, Seven working modes of FBI, FBILP, FBE, FBELP, STOP

3. A variety of communication module interfaces: Freescale microcontroller integrates various communication interface modules almost: including serial communication interface module SCI, multi-master I2C bus module, serial peripheral interface module SPI, MSCAN08 controller module, universal serial bus Module (USB/PS2)

4. With more optional modules: LCD driver module with temperature sensor, UHF transmission module, synchronous processor module, MCU with synchronous processor also has screen display module OSD, there are a few MCU has ring detection module RING and dual tone multi-frequency/tone generator DMG module

5. High reliability, strong anti-interference, multiple pin counts and package options

6. Low power consumption, perhaps the power consumption of the Freescale series of microcontrollers is not as low as that of the MSP430, but it has a full static "wait" and "stop" modes, which generally reduces your power consumption! Recently introduced several models Ultra low power consumption is comparable to MSP430!

Most used devices: MC9S12G Series

If you really want to divide one or two of these MCUs, then if you want to follow the public, there is nothing wrong with 51 MCUs; if you are looking for super cost-effective, STM32 will be your ideal choice; if you are eager for ultra-low power, MSP430 Definitely won't let you down; if you want to support domestic, STC will make you excited...