Functions of common PIC series 8-bit microcontroller chip pin symbols

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Functions of common PIC series 8-bit microcontroller chip pin symbols [Copy link]

Regarding the product performance and corresponding package pin introduction of PIC 8-bit microcontroller, beginners need to understand the meaning of each pin symbol before they can further learn and use it.

　　1. About I/O port symbols The PIC microcontroller series package has the least 8 pins (such as PIC12C5XX and PIC12C6XX), and the most can reach 84 pins (such as PIC17C76X). The number of I/O (input/output) port lines varies according to the different PIC microcontroller product models. The 8-pin package has 6 I/O port lines, while the 84-pin package has up to 66 I/O lines. These port line symbols are numbered in alphabetical order, referred to as A port, B port, C port, D port, E port, F port... Each port is 8 bits, but not necessarily 8 bits. These ports are marked with an R symbol before each port in the package pin diagram. For example, port B is marked as RB0, RB1, RB2...RB7; port E is marked as RE0, RE1...RE7; port G is marked as RG1, RG2...; and there are 6 I/O lines for the 8-pin packaged microcontroller, and the pin diagram is slightly different from the above, but GP0~GP5. The above-mentioned lines are all independently programmable bidirectional I/O lines.

　　2. Pin multiplexing function and symbol The signal pins of the microcontroller are the embodiment of the external characteristics of the microcontroller. In hardware, users can only use pins and build a microcontroller system through the connection of pins. The PIC 8-bit microcontroller series is the same as the MCS-51 series microcontroller. Except for the power supply VDD and VSS, which have a single function, the remaining signal pins often have multiple functions, that is, the multiplexing function of the pins. Common pin symbols and main functions are as follows:
　　1?MCLR/Vpp Clear (reset) input/programming voltage input. When MCLR is low, the chip is reset. The voltage on this pin cannot exceed VDD, otherwise it will enter the test method. Vpp represents the programming voltage.
　　2?OSC1/CLKIN Oscillator crystal/external clock input terminal.
　　3?OSC2/CLKOUT Oscillator crystal output terminal, connect to crystal in crystal oscillation mode, output CLKOUT signal with 1/4 frequency of OSC1 in RC mode.
　　4?TOCK1 TMRO counter input terminal, if not used, should be grounded or connected to VDD to reduce function.
　　5?TICK1 TMR1 clock input terminal.
　　6?TIOSI TMR1 oscillation input terminal.
　　7?TIOSO TMR1 oscillation output terminal.
　　8?RD, WR, CS represent parallel port read signal, write signal and chip select control line respectively.
　　9?AN0~AN7 A/D conversion analog input terminal. AN0, AN1...represent the number of channels respectively.
　　10?CCP Capture/Compare/Pulse Width Modulation and other functional terminals. CCP is the abbreviation of Capture/Compare/PWM. Some PIC chips have two CCP components, and their pins are represented by symbols CCP1 and CCP2.
　　11?SCK/SCL Synchronous serial communication clock input terminal.
　　12?TX/CK Asynchronous communication transmitter/SCI synchronous transmission clock terminal.
　　13?SDI/SDA SPI communication data input terminal.
　　14?SD0 SPI communication data output terminal.
　　15?RD0/PSP0~RD7/PSP7 D port, bidirectional programmable, can also be used as a parallel port. As a parallel port, it is TTL input, and as an I/O port, it is Schmitt input.
　　The above is the description of the package pin symbols of the PIC 8-bit microcontroller series. In addition, when reading the relevant information of the PIC 8-bit microcontroller, some letter symbols and functions are often encountered, which are also briefly introduced as follows:
　　1?OTP One-time Programming. OTP is the abbreviation of One Time Program.
　　2?RISC is short for Reduced Instruction Set Computer. RISC is the abbreviation of Reduced Instruction Set Computer.
　　3?SSP Synchronous Serial Port. SSP is the abbreviation of Synchronous Serial Port.
　　4?SCI Serial Communication Interface. SCI is the abbreviation of Serial Communication Interface.
　　5?USART Full-duplex Universal Serial Asynchronous Receiver Transmitter. USART is the abbreviation of Universal Serial Aosynchronous Receiver Transmitter.
　　6?UART Universal Asynchronous Receiver Transmitter.
　　7?POR Power-on Reset. POR is the abbreviation of Power On Reset.
　　8?OST Oscillator Start-up Timer. OST is the abbreviation of Oscillator Start－up Timer.
　　9?PWRT Power-on Delay Timer. PWRT is the abbreviation of Power－up Timer.
　　10?SFR Special Function Register. SFR is the abbreviation of Special Function Register.
　　11?PWM Pulse Width Modulator. PWM is the abbreviation of Pulse Width Modulation.
　　12?MIPS Million instructions can be executed per second. MIPS is the abbreviation of Million Instructions Per Second.