#include<stdio.h> #include<stdlib.h> //异或法 unsigned char byteReverse(unsigned char val) { int i; for (i = 0; i < 4; i++) { if (((val &(1 << i)) >> i) ^ ((val & (1 << (7 - i))) >> (7 - i))) val ^= (1 << i) | (1 << (7 - i)); } return val; } //移位法: unsigned char byteReverse1(unsigned char value) { unsigned char a = 0, b = 0, c = 0; for (int i=0;i<4;i++) { a = value&(0x80>>i); b = value&(0x01 << i); c = c + (b << (7 - 2 * i)) + (a >> (7 - 2 * i)); } return c; } //如用C语言,“蝶形交换”最好 unsigned char byteReverse2(unsigned char a) { a = (a << 4) | (a >> 4); a = ((a << 2) & 0xcc) | ((a >> 2) & 0x33); a = ((a << 1) & 0xaa) | ((a >> 1) & 0x55); return a; } //蝶形交换,下面三句顺序随意 unsigned char byteReverse3(unsigned char a) { a = ((a << 4) & 0xf0) | ((a >> 4) & 0x0f); a = ((a << 2) & 0xcc) | ((a >> 2) & 0x33); a = ((a << 1) & 0xaa) | ((a >> 1) & 0x55); return a; } //还是觉得查表简单点: unsigned char byteReverse4(unsigned char dat) { const unsigned char table[16] = { 0, 0x08, 0x04, 0x0c, 0x02, 0x0a, 0x06, 0x0e, 0x01, 0x09, 0x05, 0x0d, 0x03, 0x0b, 0x07, 0x0f }; dat = table[(dat & 0xf0) >> 4] | (table[dat & 0x0f] << 4); return dat; } unsigned char byteReverse5(unsigned char data) { unsigned char ret = 0; for (unsigned char i = 0; i< 8; i++) { ret <<= 1; if (data & 0x01) { ++ret; } data >>= 1; } return ret; } unsigned char byteReverse6(unsigned char val) { unsigned char dat_b, i; dat_b = 0x00; for (i = 0; i <= 7; i++) { dat_b = dat_b | ((val >> i) & 0x01); if (i == 7)break; dat_b = dat_b << 1; } val = dat_b; return val; } void byteReverse7(unsigned char tar, unsigned char *pdata) { unsigned char temp1 = (tar & 0x80) >> 7; unsigned char temp2 = (tar & 0x40) >> 5; unsigned char temp3 = (tar & 0x20) >> 3; unsigned char temp4 = (tar & 0x10) >> 1; unsigned char temp5 = (tar & 0x08) << 1; unsigned char temp6 = (tar & 0x04) << 3; unsigned char temp7 = (tar & 0x02) << 5; unsigned char temp8 = (tar & 0x01) << 7; *pdata = (temp1) | (temp2) | (temp3) | (temp4) | (temp5) | (temp6) | (temp7) | (temp8); } //有问题 const unsigned char jh_tab[8] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 }; unsigned char byteReverse8(unsigned char in_data) { unsigned char i; unsigned char aa[8]; unsigned char back_data = 0; for (i = 0; i< 8; i++) { aa[i] = in_data & jh_tab[i]; } aa[0] = aa[0] << 7; aa[1] = aa[1] << 5; aa[2] = aa[2] << 3; aa[3] = aa[3] << 1; aa[7] = aa[7] >> 7; aa[6] = aa[6] >> 5; aa[5] = aa[5] >> 3; aa[4] = aa[4] >> 1; for (i = 0; i< 8; i++) { back_data = back_data + aa; } back_data = back_data; return back_data; } void byteReverse9() { unsigned char c = 0x20; unsigned char b = 0; char i; unsigned char P1 = c; unsigned char P2 = b; for (i = 0; i< 8; i++) { b <<= 1; b += c & 0x01; c >>= 1; P1 = c; P2 = b; } while (1); } void main() { char data = 0x96; printf("@@@@@%x\n", byteReverse1(data)); } /* //汇编法 #ifndef_COMMON_H_ #define_COMMON_H_ #define__SWAP7_0(_short)\ (__extension__({ \ uint8_t __result = (uint8_t)(_short); \ __asm__ __volatile__ \ ( \ "mov__tmp_reg__,%0" "\n\t" \ "ldir25,8" "\n\t" \ "L_%=:" "lsr__tmp_reg__" "\n\t" \ "rol%0" "\n\t" \ "decr25" "\n\t" \ "brneL_%=" "\n\t" \ : "=r" (__result) \ : "0" (__result) \ : "memory" \ ); \ __result; \ })) #defineSWAP7_0(_short)__SWAP7_0((uint8_t)(_short)) #endif int main(void) { char i; i = 0b01100111; i = SWAP7_0(i); PORTB = i; } */