2字节16进制数转整数

// @file test.cpp
// @brief 试验一下2字节16进制数转整数
// modbus 回包一个寄存器是2个字节, 如果这2个字节表示的是一个short int, 用程序转一下. 强转也可以.

#include 
#include 

// 2字节16进制数转int
int WORD_2_int(unsigned short int wIn);

int main()
{
	unsigned short int wIn = 0;

	wIn = 0xFF9F;
	printf("0x%x = %dn", wIn, WORD_2_int(wIn));
	// 0xff9f = -97
	
	wIn = 0x0061;
	printf("0x%x = %dn", wIn, WORD_2_int(wIn));
	// 0x61 = 97

	return EXIT_SUCCESS;
}

int WORD_2_int(unsigned short int wIn)
{
	int i_rc = 0;
	int i_sign = 1;

	i_sign = ((wIn & (1 << 15)) > 0) ? -1 : 1;
	if (i_sign < 0)
	{
		// wIn &= ~(1 << 15); // 去掉符号位
		wIn -= 1;
		i_rc = (~wIn & 0xffff);
	}
	else {
		i_rc = wIn;
	}

	i_rc *= i_sign;

	return i_rc;
}