1. Increase word length to improve data accuracy and processing speed.
Early microcontrollers had a word length of 8 bits, followed by 16-bit, 24-bit, and 32-bit microcontrollers. However, in most applications, 8 bits of data are sufficient. Therefore, like 16-bit, 24-bit, and 32-bit microcontrollers, 8-bit microcontrollers are still undergoing development in areas such as architecture, integration of multi-functional components, pipeline and parallel processing technologies, manufacturing processes, and clock frequencies.
2. Improve manufacturing processes to enhance the overall performance of the microcontroller.
With the development of integrated circuit technology, microcontroller manufacturing has evolved from MOS type to CMOS and HCMOS type, thereby improving chip integration and operating speed while reducing voltage and power consumption. Internally, large-capacity Flash memory is used to enable technologies such as in-system programming (ISP) and in-application programming (IAP). For example, Philips' P89C51RC2/P89C51RD2 has 32KB/64KB Flash memory and integrates boot and erase/programming functions; the external clock frequency has increased to 33 MHz~40 MHz, and the operating speed reaches 50 M/s~100 M/s.
3. Shift from Complex Instruction Set Computing (CISC) to Reducing Instruction Set Computing (RISC) Technology
Early MCS 51 microcontrollers used CISC (Complex Instruction Set Computer) technology. With the development of RISC (Reduced Instruction Set Computer) technology, microcontrollers also adopted this technology, which simplified the architecture and improved the CPU speed, such as Microchip's PIC12F×××, PIC16F×××, PIC17F×××, and PIC18F××× microcontrollers.
18. Microcontroller Principles and Interface Technology
4. Multifunctional module integration technology enables a single "embedded" chip to have multiple functions.
In new microcontrollers, in addition to RAM/ROM, file registers, timers/counters, parallel/serial interface circuits, V/F converters, and A/D and D/A circuits, many microcontrollers now adopt dual-CPU or multi-CPU structures, adding phase-locked loops, USB, CAN, ISSC, I2C and other bus interfaces, and providing TCP/IP protocol communication interfaces. This improves the microcontroller's numerical calculation, data acquisition and processing capabilities, and provides the ability to transmit external data and connect to communication networks. For example, Echelon's Neuron3150 has three built-in CPUs: one for media access, one for data processing, and one for network processing. Philips' P89C66× also provides I2C bus transmission.
5. Combination of microprocessor and DSP technologies
New microcontrollers combine microprocessors with DSP (Digital Signal Processor) technology to address the high-speed, real-time processing requirements of network and multimedia technologies. For example, the μ′nsp series microcontrollers from Sunplus Technology Co., Ltd. in Taiwan incorporate DSP functionality into their 16-bit microcontrollers, providing voice encoding and decoding capabilities, and featuring a built-in in-circuit emulator (ICE).
6. Compilers integrated with high-level languages
The new microcontroller incorporates a high-level compiler, supports the use of application programming interfaces (APIs), and supports high-level languages such as C and hardware description languages (VHDL). It also has a built-in in-circuit emulation circuit (ICE) and supports in-circuit programming, namely ISP and IAP technologies.
7. Low voltage, wide voltage range, low power consumption
New microcontrollers prioritize low voltage, wide voltage range, and low power consumption. They have improved manufacturing processes and reduced internal voltage and power consumption.
It offers a wide voltage operating range to support the needs of different applications. For example, the XE8301 from the Swedish company Xemic operates at a voltage of 1.2V to 5.5V, and draws 200 μA when the operation speed is 1 M/s; in standby mode, the current is only 1 μA.
Features of a microcontroller
Microcontrollers have the following main characteristics.
(1) It has an excellent performance-price ratio.
(2) High integration, small size, and high reliability. The microcontroller integrates all functional components onto a single chip and adopts an internal bus structure, reducing the interconnections between chips and greatly improving the reliability and anti-interference capability of the microcontroller. In addition, its small size makes it easy to take measures for strong magnetic field environments, making it suitable for working in harsh environments; it is also easy to commercialize.
(3) Strong control functions. To meet the requirements of industrial control, microcontrollers generally have a rich set of transfer instructions, I/O port logic operations, and bit processing instructions in their instruction sets. Generally speaking, the logic control functions and operating speed of microcontrollers are higher than those of microcomputers of the same level.
(4) The system expansion and system configuration of the microcontroller are relatively typical and standardized, and it is very easy to form application systems of various sizes.
Due to these significant characteristics, the application scope of microcontrollers is expanding daily. The application of microcontrollers has broken with traditional design thinking; many functions that were previously implemented using analog circuits, pulse digital circuits, and logic components can now be accomplished using microcontrollers and software.
