NXP Freescale Kinetis KEA128 Study Notes 3--GPIO Module (I)

The KEA128 chip has 7 groups of IO, PORTA--H has 8 pins in each group, and PORTI has 7 pins, totaling 71 pins.

The driving capacity of each pin is 2.5mA, and all pins can be pulled up to VDD internally, without internal pull-down. Unused pins should be pulled up internally through programming.

When the MCU is in the running, waiting, or debugging mode, the GPIO works normally. In the stop mode, the GPIO stops working.

The following is an introduction to the port control registers, mainly the port filter register, the pull-up enable register and the high drive capability enable register

GPIO has three groups of registers, namely GPIOA, GPIOB, and GPIOC. Each group has 7 registers, namely output register (PDOR), output set register (PSOR), output clear register (PCOR), output reverse register (PTOR), input register (PDIR), data direction register (PDDR), and input disable register (PIDR).

GPIO programming steps:

1. Set GPIO as input or output and set the data direction register

2. If it is output, set the value of GPIO, low 0 high 1

3. If it is input, get the pin status through the input register. Low 0 High 1.

//===========================================================================

//File name: common.h

//Functional overview: Common element header file

//Copyright: Freescale Embedded Center, Soochow University (sumcu.suda.edu.cn)

//Version update: 2015-06-05 V2.0

//Chip type: KEA128

//===========================================================================

#ifndef __COMMON_H //Prevent duplicate definition (starting with _COMMON_H)

#define __COMMON_H

// 1. Chip register mapping file and processor core attribute file

#include "core_cmFunc.h"

#include "core_cmInstr.h"

#include "core_cm0plus.h"

#include "SKEAZ1284.h" // Include chip header file

#include "system_SKEAZ1284.h" // Include chip system initialization file

#define SYSTEM_CLK_KHZ DEFAULT_SYSTEM_CLOCK/1000 // Chip system clock frequency (KHz)

#define CORE_CLK_KHZ SYSTEM_CLK_KHZ //Chip core clock frequency (KHz)

#define BUS_CLK_KHZ SYSTEM_CLK_KHZ/2 //Chip bus clock frequency (KHz)

// 2. Define the switch interrupt

#define ENABLE_INTERRUPTS __enable_irq // Enable general interrupt

#define DISABLE_INTERRUPTS __disable_irq // Disable total interrupt

// 3. Bit operation macro function (setting, clearing, obtaining the status of a register bit)

#define BSET(bit,Register) ((Register)|= (1<<(bit))) // Set a bit in the register

#define BCLR(bit,Register) ((Register) &= ~(1<<(bit))) // Clear one bit of the register

#define BGET(bit,Register) (((Register) >> (bit)) & 1) // Get the status of a bit in the register

// 4. Redefine basic data types (type alias macro definition)

typedef unsigned char uint_8; // unsigned 8-bit number, byte

typedef unsigned short int uint_16; // unsigned 16-bit number, word

typedef unsigned long int uint_32; // unsigned 32-bit number, long word

typedef char int_8; // Signed 8-bit number

typedef short int int_16; // signed 16-bit number

typedef int int_32; // signed 32-bit number

// Do not optimize type

typedef volatile uint_8 vuint_8; // Do not optimize unsigned 8-bit numbers, bytes

typedef volatile uint_16 vuint_16; // Do not optimize unsigned 16-bit numbers, word

typedef volatile uint_32 vuint_32; // Do not optimize unsigned 32-bit numbers, long words

typedef volatile int_8 vint_8; // Do not optimize signed 8-bit numbers

typedef volatile int_16 vint_16; // Do not optimize signed 16-bit numbers

typedef volatile int_32 vint_32; // Do not optimize signed 32-bit numbers

#endif //Prevent duplicate definition (ending with _COMMON_H)

//===========================================================================

//File name: gpio.h

//Functional summary: GPIO underlying driver component header file

//Copyright: Freescale Embedded Center, Soochow University (sumcu.suda.edu.cn)

//Version update: 2015-06-05 V2.0

//Chip type: KEA128

//===========================================================================

#ifndef GPIO_H //Prevent duplicate definition (starting with GPIO_H)

#define GPIO_H

#include "common.h" //Includes common element header files

//Port number address offset macro definition

#define PORTA    (0<<8)

#define PORTB    (1<<8)

#define PORTC    (2<<8)

#define PORTD    (3<<8)

#define PORTE    (4<<8)

#define PORTF    (5<<8)

#define PORTG    (6<<8)

#define PORT (7<<8)

#define PORTS (8<<8)

//pin direction macro definition

#define GPIO_IN      0

#define GPIO_OUTPUT  1

//===========================================================================

//Function name: gpio_init

//Function returns: None

//Parameter description: port_pin: (port number)|(pin number) (e.g.: PORTB|(5) means pin 5 of port B)

// dir: pin direction (0 = input, 1 = output, can be defined by pin direction macro)

// state: initial state of the port pin (0 = low level, 1 = high level)

//Functional summary: Initialize the specified port pin as a GPIO pin function and define it as input or output. If it is output,

// Also specify whether the initial state is low or high

//===========================================================================

void gpio_init(uint_16 port_pin, uint_8 dir, uint_8 state);

//===========================================================================

//Function name: gpio_set

//Function returns: None

//Parameter description: port_pin: (port number)|(pin number) (e.g.: PORTB|(5) means pin 5 of port B)

// state: the port pin state you want to set (0 = low level, 1 = high level)

//Function Summary: When the specified port pin is defined as GPIO function and is output, this function sets the pin status

//===========================================================================

void gpio_set(uint_16 port_pin, uint_8 state);

//===========================================================================

//Function name: gpio_get

//Function returns: the state of the specified port pin (1 or 0)

//Parameter description: port_pin: (port number)|(pin number) (e.g.: PORTB|(5) means pin 5 of port B)

//Function summary: When the specified port pin is defined as GPIO function and is input, this function obtains the specified pin status

//===========================================================================

uint_8 gpio_get(uint_16 port_pin);

//===========================================================================

//Function name: gpio_reverse

//Function returns: None

//Parameter description: port_pin: (port number)|(pin number) (e.g.: PORTB|(5) means pin 5 of port B)

//Function Summary: When the specified port pin is defined as GPIO function and is output, this function inverts the pin state

//===========================================================================

void gpio_reverse(uint_16 port_pin);

//===========================================================================

//Function name: gpio_pull

//Function returns: None

//Parameter description: port_pin: port number | pin number (e.g.: PORTB|(5) means pin 5 of port B)

// pullselect: pin pull-up enable selection (0 = pull-up disabled, 1 = pull-up enabled)

//Function summary: Pull the specified pin high

//===========================================================================

void gpio_pull(uint_16 port_pin, uint_8 pullselect);

#endif //Prevent duplicate definition (end of GPIO_H)

//===========================================================================

//statement:

//（1）The source code we developed has passed the test of the hardware system provided by our center. We sincerely contribute it to the society. If there are any shortcomings, please feel free to point them out.

//(2) For users who use hardware systems other than those of our center, please carefully match the system according to your own hardware when porting the code.

//

//Freescale Embedded Center, Suzhou University

//Technical consultation: 0512-65214835 http://sumcu.suda.edu.cn

//===========================================================================

//File name: gpio.c

//Functional summary: GPIO underlying driver component source file

//Copyright: Freescale Embedded Center, Soochow University (sumcu.suda.edu.cn)

//Version update: 2015-06-05 V2.0

//Chip type: KEA128

//===========================================================================

#include "gpio.h" //Include this component header file

uint_32 bit; //Internal variable used to record the offset of the pin in the port register

//Internal function declaration

//Parse the port number and pin

static void gpio_port_pin_num(uint_16 port_pin,uint_8* port,uint_8* pin);

// Parse the base address and the pin's offset in the register

static void gpio_ptr_bit(uint_16 port_pin,GPIO_MemMapPtr* gpio_ptr,uint_32* bit);

//===========================================================================

//Function name: gpio_init

//Function returns: None

//Parameter description: port_pin: (port number)|(pin number) (e.g.: PORTB|(5) means pin 5 of port B)

// dir: pin direction (0 = input, 1 = output, can be defined by pin direction macro)

// state: initial state of the port pin (0 = low level, 1 = high level)

//Functional summary: Initialize the specified port pin as a GPIO pin function and define it as input or output. If it is output,

// Also specify whether the initial state is low or high

//===========================================================================

void gpio_init(uint_16 port_pin, uint_8 dir, uint_8 state)

{

//Local variable declaration

GPIO_MemMapPtr gpio_ptr; //Declare port_ptr as a GPIO structure type pointer

gpio_ptr_bit(port_pin,&gpio_ptr,&bit); //Calculate the base address and the offset of the pin in the register

//Determine whether the pin is output or input based on the parameter dir

if (1 == dir) // hope for output

{

//Port data direction register is defined as output

BSET(bit, GPIO_PDDR_REG(gpio_ptr)); //1 is general output, 0 is input

// Output clear register

BSET(bit, GPIO_PCOR_REG(gpio_ptr)); //This register is set to 1, and the pin output is set to 0

//The initial state is low level

gpio_set(port_pin, state); //Call gpio_set function to set the initial state of the pin

} 

else