Customize the reg52.h header file (key knowledge points of microcontroller learning)

/*--------------------------------------------------------------------------

Custom REG52 header file

@auth lei

@date 2017-05

--------------------------------------------------------------------------*/

#ifndef __REG52_H__

#define __REG52_H__

/* One byte register */

sfr P0 = 0x80; //Bidirectional IO, external output needs to be connected to a pull-up resistor

sfr P1 = 0x90; //quasi-bidirectional IO, as input, it must be set to 1 first

sfr P2 = 0xA0; //quasi-bidirectional IO, as input, it must be set to 1 first

sfr P3 = 0xB0; //quasi-bidirectional IO, as input, it must be set to 1 first, and has a second function

sfr PSW = 0xD0;

sfr ACC   = 0xE0;

sfr B     = 0xF0;

sfr SP    = 0x81;

sfr DPL   = 0x82;

sfr DPH   = 0x83;

sfr PCON  = 0x87;

sfr TCON = 0x88; //Interrupt control register

sfr TMOD = 0x89; //Timer working mode register

sfr TL0 = 0x8A; //Timer/Counter 0 low 8 bits

sfr TL1 = 0x8B; //Timer/Counter 1 low 8 bits

sfr TH0 = 0x8C; //Timer/Counter 0 high 8 bits

sfr TH1 = 0x8D; //Timer/Counter 1 high 8 bits

sfr IE = 0xA8; //Interrupt enable register

sfr IP = 0xB8; //Interrupt priority register

sfr SCON = 0x98;

sfr SBUF  = 0x99;

/* 8052 MCU extended registers */

sfr T2CON = 0xC8;

sfr RCAP2L = 0xCA;

sfr RCAP2H = 0xCB;

sfr TL2    = 0xCC;

sfr TH2    = 0xCD;

/* One bit register */

/*  PSW  */

sbit CY = PSW^7;

sbit AC = PSW^6;

sbit F0 = PSW^5;

sbit RS1 = PSW^4;

sbit RS0 = PSW^3;

sbit OV = PSW^2;

sbit P = PSW^0; //8052 specific

/*------------Detailed explanation of interruption content----------------------------

* Related registers

* 1.IE interrupt enable register

* 2.TCON timing control register

* 3.IP interrupt priority register (not commonly used)

* 4.TMOD timer working mode register (only used for timer/counter interrupt)

*Steps to use interrupts:

* 1. Interrupt initialization function (only need to be called once, do not put it in a loop and call it repeatedly)

* 2. Write interrupt handling function

* 3. Call the interrupt initialization function in the main function

*------------Detailed explanation of interruption content----------------------------/

/* TCON timing control register */

sbit TF1 = TCON^7; // Flag bit in timer/counter:

sbit TR1 = TCON^6; //Timer/counter 1 starts and stops:

sbit TF0 = TCON^5; //0 flag bit in timer/counter:

sbit TR0 = TCON^4; //Timer/Counter Interrupt 0 start, stop:

sbit IE1 = TCON^3; //External interrupt 1 interrupt flag: hardware set to 1 when an interrupt occurs, hardware set to 0 after the interrupt function is processed

sbit IT1 = TCON^2; //External interrupt 1 trigger mode: 0 for level, 1 for falling edge

sbit IE0 = TCON^1; //External interrupt 0 interrupt flag: hardware set to 1 when an interrupt occurs, hardware set to 0 after the interrupt function is processed

sbit IT0 = TCON^0; //External interrupt 0 trigger mode: 0 is level, 1 is falling edge

/* IE interrupt enable register */

sbit EA = IE^7; //interrupt master switch

sbit ET2 = IE^5; // 8052 specific

sbit ES = IE^4;

sbit ET1 = IE^3; //Timer/Counter Interrupt 1 Switch

sbit EX1 = IE^2; //External interrupt 1 switch

sbit ET0 = IE^1; //Timer/Counter Interrupt 0 Switch

sbit EX0 = IE^0; //External interrupt 0 switch

/* IP interrupt priority register */

sbit PT2 = IP^5;

sbit PS = IP^4;

sbit PT1 = IP^3;

sbit PX1 = IP^2;

sbit PT0 = IP^1;

sbit PX0 = IP^0;

/*------------------Detailed explanation of TMOD register-----------------

The 8 bits from high to low are: GATE C/T M1 M0 GATE C/T M1 M0

{----Configure timer 1----} {----Configure timer 0----}

GATE: Gating bit, the external pin (T0, T1) is used as the main switch to start the timer: when GATE=0, T0 and T1 are invalid; when GATE=1, the timer can only be started when T0 or T1 switch is turned on (high level)

C/T: Counting mode selection, when C/T=0, it is used as a timer, when C/T=1, it is used as a counter

M1, M0: working mode selection bit, 00 is working mode 0, 13-bit timer/counter, TH stores the upper 8 bits, TL stores the lower 5 bits

01 is working mode 1, 16-bit timer/counter, TH stores the upper 8 bits, TL stores the lower 8 bits (commonly used)

10 is working mode 2, 8-bit timer/counter with automatic initial value loading (commonly used)

11 is working mode 3, T0 is divided into two 8-bit independent counters, and T1 stops working

*------------------Detailed explanation of TMOD register-----------------/

/* The second function of P3 port */

sbit RD = P3^7; // external memory read strobe signal

sbit WR = P3^6; //External memory write select signal

sbit T1 = P3^5; // Start of external control timer/counter 1 (valid only when bit 7 of TMOD register GATE = 1), 1 means start, 0 means stop

sbit T0 = P3^4; // Start of external control timer/counter 0 (valid only when bit 3 of TMOD register GATE = 1), 1 means start, 0 means stop

sbit INT1 = P3^3; //External interrupt 1 input

sbit INT0 = P3^2; //External interrupt 0 input

sbit TXD = P3^1; //Serial output

sbit RXD = P3^0; //Serial input

/* SCON serial port control register */

sbit SM0 = SCON^7;

sbit SM1 = SCON^6;

sbit SM2   = SCON^5;

sbit REN   = SCON^4;

sbit TB8 = SCON^3;

sbit RB8   = SCON^2;

sbit TI = SCON^1;

sbit RI = SCON^0;

/* P1 port second function */

sbit T2EX = P1^1; // 8052 only

sbit T2 = P1^0; // 8052 specific

/* T2CON */

sbit TF2 = T2CON^7;

sbit EXF2 = T2CON^6;

sbit RCLK = T2CON^5;

sbit TCLK = T2CON^4;

sbit EXEN2 = T2CON^3;

sbit TR2 = T2CON^2;

sbit C_T2 = T2CON^1;

sbit CP_RL2 = T2CON^0;

#endif