AVR microcontroller, STC microcontroller, Freescale microcontroller introduction?
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, 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.
Features 2. The dedicated registers of the AVR are concentrated in the 00~3F address range. It is not necessary to select the bank before the PIC, which is more convenient to use than the 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. The general-purpose registers of the 51 series are up to 128 (four times that of the AVR), and this is not the case when programming.
Features 3. The I/O pin of the AVR is similar to the PIC. It also has a direction register for controlling the 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. C language and 51 C language are very different in writing, which makes friends who are learning 51 MCU very unaccustomed
2. There is no bit operation, it is to control and judge the relevant register bits in bytes.
3. There are a total of 32 general-purpose registers (R0 to R31), and the first 16 registers (R0 to R15) cannot directly interact with the immediate data, so the versatility is degraded. 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
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 microcontroller in China. 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 available on STC. At the same time, STC is 51 core, which is based on 51 MCU.
Engineers have provided great convenience, eliminating the need to learn AVR time, 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 supplier control of the motor, strong interference occasions, has become a new series of single-chip microcomputer after 51 single-chip microcomputer.
The characteristics are as follows:
Feature 1: 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 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 instruction set.
Features 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
Feature 3: Download the burning 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)
Most used device: STC12C2052AD
Freescale microcontroller
Mainly for S08, S12 such microcontrollers, of course, Freescale microcontroller is far from this. The Freescale series of single-chip microcomputers adopt Harvard structure and pipeline instruction structure, which exhibits low cost and high performance in many fields. Its architecture saves a lot of time for product development. In addition, Freescale offers a variety of integrated modules and bus interfaces that can be used more flexibly in different systems! The unique features of the Freescale microcontroller are as follows:
1. Has 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, and a few MCU has ring detection module RING and dual tone multi-frequency/tone generator DMG module
2. 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
3. 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 oscillator, or internal clock, most CPUs have the above three modules at the same time! Can run in seven working modes: FEI, FEE, FBI, FBILP, FBE, FBELP, STOP
4. 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 to reduce your power consumption overall! Several ultra-low power consumptions have recently been introduced that are comparable to the MSP430!
5. 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)
6. High reliability, strong anti-interference, multiple pin counts and package options
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...
If you want to know more, our website has product specifications for AVR microcontroller, STC microcontroller, Freescale microcontroller, you can go to ALLICDATA ELECTRONICS LIMITED to get more information