GCC AVR (ATMEL studio+ AVR studio) how to define the structure array in the program memory (flash) space and read it

One 、 Defining structure

To add #include <avr/io.h>.

#include <avr/io.h>

Then define the following structure . 

	typedef struct tagFORMAT_SET_STRUCT
	{
    	uint8_t Decimal;
    	int16_t Min;
    	int16_t Max;
    	int16_t Default;
	} FORMAT_SET_STRUCT,*FORMAT_SET_STRUCT_PTR;

Two 、 Add header file <avr/pgmspace.h>

Only add header files <avr/pgmspace.h> To program memory （flash） Definition and read operation of .

#include <avr/pgmspace.h>

3、 ... and 、 Use keywords  PROGMEM const  Define an array of structures

PROGMEM const FORMAT_SET_STRUCT SET_DEFAULT_BUFFER[30] = {

{0x00 ,    0 , 9999 ,    0},	
{0x01 ,    0 , 1000 ,    0},	
{0x03 ,    0 , 29999 , 2430},	
{0x03 ,    0 , 29999 , 280},
{0x03 ,    0 , 29999 ,    0},	

{0x01 ,    0 ,    8 ,    6},	
{0x01 ,    0 ,  100 ,    0},	
{0x00 ,    0 ,    3 ,    0},	
{0x00 ,    1 ,    2 ,    2},	
    
{0x00 ,    0 ,    1 ,    0},	
{0x01 ,    0 ,  200 ,  100},	
{0x00 ,    0 ,    1 ,    0},	
{0x00 ,  -40 ,   40 ,    4},	

{0x00 ,    1 ,  200 ,    1},	
{0x00 ,    0 ,    8 ,    6},	
{0x00 ,    0 ,    2 ,    0},	
{0x00 ,    0 ,    1 ,    0},	

{0x00 ,    0 , 32767 , 1206},	
{0x00 ,    0 , 32767 , 6341},	
{0x00 ,    0 , 32767 , 350},	
{0x00 ,    0 , 32767 , 2410},	
{0x00 ,    0 , 32767 , 4218},	
{0x00 ,    0 , 32767 , 21006},
{0x00 ,    0 , 32767 , 4222},	
{0x00 ,    0 , 32767 , 21035},	

{0x00 ,    0 , 4095 ,  812},	
{0x00 ,    0 , 4095 , 3862},	
{0x00 ,    0 , 4095 ,  694},	
{0x00 ,    0 , 4095 , 3488},	
{0x00 ,    0 ,    1 ,    0},  
};

Four 、 Structure array read operation

1、 Read the 16 Digit value , Use pgm_read_word(&) Library function

for example ：

int16_t m;

m = pgm_read_word(&SET_DEFAULT_BUFFER[0].Default);

2、 Read the 8 Digit value , Use pgm_read_byte(&) Library function

for example ：

uint8_t n;

n = pgm_read_byte(&SET_DEFAULT_BUFFER[1].Decimal);