What is the main composition of CPU of 51 Single Chip Microcomputer
The CPU of 51 single chip microcomputer consists of CPU, ram, ROM, timer / counter, parallel I / O port, interrupt control system, timing and control unit.
Single chip microcomputer is a kind of integrated circuit chip, which uses VLSI technology to integrate CPU, ram, ROM, various I / O ports and interrupt system, timer / counter and other functions (including display drive circuit, pulse width modulation circuit, analog multiplexer, a / D converter and other circuits) with data processing capability into the system- A small and perfect microcomputer system on a piece of silicon is widely used in the field of industrial control. From the 1980s, from the then 4-bit, 8-bit microcontroller, to now 300m high-speed microcontroller.
What is the word length of 51 MCU
1. The main difference between 8031 and 8051 is that 8051 has_ Program memory
2. The function of / RD pin in MCU pin is to read off chip data memory_ The signal direction is outward from 51 series, the function of T1 pin is the external counting input of timer 1, and the direction is inward from 51 series.
3. The CY bit in PSW register is the carry flag bit, which can be used as the carry flag_ Setb C or CLR C is set or cleared.
4. In MSC-51 single chip microcomputer, the only 16 bit register that users can use is_ DPTR。
5. The two commands to access program memory are:_ MOVC A，@A+PC;、MOVC A，@A+DPTR 。
The main products of 51 single chip microcomputer
*Intel: 80C31, 80C51, 87C51, 80C32, 80C52, 87c52, etc;
*ATMEL: 89C51, 89C52, 89C2051, 89S51 (RC), 89S52 (RC), etc;
*Many products of Philips, Huabang, Dallas, Siemens, etc;
STC: 89C51, 89C52, 89c516, 90c516 and many other brands.