The STC89C52 is a low-voltage, high-performance COMOS8 microprocessor with 8K bytes of Programmable Readable Memory (FPEROM-Flash Programable and Erasable Read Only Memory). The device is fabricated using ATMEL's dense-non-volatile memory manufacturing technology and is compatible with the industry-standard MCS-51 instruction set and output pins. STC89C52 pin diagram, schematic, as shown below: The STC89C52 pin is described as follows: 1 main power pin (2) VCC (Pin40): power input, connect +5V power supply GND (Pin20): Ground wire 2 external crystal oscillator pins (2) XTAL1 (Pin19): input terminal of the on-chip oscillator circuit XTAL2 (Pin20): output of the on-chip oscillator circuit 3 control pins (4) RST/VPP (Pin9): Reset pin, a high level of 2 machine cycles on the pin will reset the microcontroller. ALE/PROG (Pin30): address latch enable signal PSEN (Pin29): external memory read strobe signal EA/VPP (Pin31): Internal and external strobe of program memory. Connected low to read from external program memory. If connected high, read instruction from internal program memory. 4 programmable input / output pins (32) STC89C52 MCU has 4 groups of 8-bit programmable I/O ports, which are respectively P0, P1, P2, P3, each port has 8 bits (8 pins), a total of 32. PO port (Pin39~Pin32): 8-bit bidirectional I/O port line, named P0.0~P0.7 P1 port (Pin1~Pin8): 8-bit quasi-bidirectional I/O port line, named P1.0~ P1.7 P2 port (Pin21~Pin28): 8-bit quasi-bidirectional I/O port line, named P2.0~P2.7 P3 port (Pin10~Pin17): 8-bit quasi-bidirectional I/O port line, named P3.0～P3.7 The main functions of the STC89C52 are shown in the following table: Main function Jinhu Weibao Trading Co., Ltd , https://www.weibaoe-cigarette.com
