单片机中整数循环左移 单片机C语言
\u6574\u6570\u53f3\u79fb\u95ee\u9898?m>>n
\u610f\u601d\u662f\u5c06m\u7684\u4e8c\u8fdb\u5236\u6570\u53f3\u79fbn\u4f4d
\u6bd4\u5982\u8bf48>>2 \u7ed3\u679c\u662f2
\uff088\u4e8c\u8fdb\u5236\u4e3a1000\uff0c\u53f3\u79fb2\u4f4d\uff0c\u53730010\uff0c\u4e5f\u5c31\u662f\u5341\u8fdb\u5236\u76842\uff09
#include
c51\u4e2d\u7684intrins.h\u5e93\u51fd\u6570
_crol_ \u5b57\u7b26\u5faa\u73af\u5de6\u79fb
_cror_ \u5b57\u7b26\u5faa\u73af\u53f3\u79fb
_irol_ \u6574\u6570\u5faa\u73af\u5de6\u79fb
_iror_ \u6574\u6570\u5faa\u73af\u53f3\u79fb
_lrol_ \u957f\u6574\u6570\u5faa\u73af\u5de6\u79fb
_lror_ \u957f\u6574\u6570\u5faa\u73af\u53f3\u79fb
_nop_ \u7a7a\u64cd\u4f5c8051 NOP \u6307\u4ee4
_testbit_ \u6d4b\u8bd5\u5e76\u6e05\u96f6\u4f4d8051 JBC \u6307\u4ee4
\u8be6\u89e3\uff1a
\u51fd\u6570\u540d\uff1a _crol_\uff0c_irol_\uff0c_lrol_
\u539f \u578b\uff1a unsigned char _crol_(unsigned char val,unsigned char n);
unsigned int _irol_(unsigned int val,unsigned char n);
unsigned int _lrol_(unsigned int val,unsigned char n);
\u529f \u80fd\uff1a_crol_\uff0c_irol_\uff0c_lrol_\u4ee5\u4f4d\u5f62\u5f0f\u5c06val \u5de6\u79fbn \u4f4d\uff0c\u8be5\u51fd\u6570\u4e0e8051\u201cRLA\u201d\u6307\u4ee4
\u76f8\u5173\uff0c\u4e0a\u9762\u51e0\u4e2a\u51fd\u6570\u4e0d\u540c\u4e8e\u53c2\u6570\u7c7b\u578b\u3002
\u4f8b\uff1a
#include
main()
{
unsigned int y;
C-5 1 \u7a0b\u5e8f\u8bbe\u8ba1 37
y=0x00ff;
y=_irol_(y,4); /*y=0x0ff0*/
}
\u51fd\u6570\u540d\uff1a _cror_\uff0c_iror_\uff0c_lror_
\u539f \u578b\uff1a unsigned char _cror_(unsigned char val,unsigned char n);
unsigned int _iror_(unsigned int val,unsigned char n);
unsigned int _lror_(unsigned int val,unsigned char n);
\u529f \u80fd\uff1a_cror_\uff0c_iror_\uff0c_lror_\u4ee5\u4f4d\u5f62\u5f0f\u5c06val \u53f3\u79fbn \u4f4d\uff0c\u8be5\u51fd\u6570\u4e0e8051\u201cRRA\u201d\u6307\u4ee4
\u76f8\u5173\uff0c\u4e0a\u9762\u51e0\u4e2a\u51fd\u6570\u4e0d\u540c\u4e8e\u53c2\u6570\u7c7b\u578b\u3002
\u4f8b\uff1a
#include
main()
{
unsigned int y;
y=0x0ff00;
y=_iror_(y,4); /*y=0x0ff0*/
}
\u51fd\u6570\u540d\uff1a _nop_
\u539f \u578b\uff1a void _nop_(void);
\u529f \u80fd\uff1a_nop_\u4ea7\u751f\u4e00\u4e2aNOP \u6307\u4ee4,\u8be5\u51fd\u6570\u53ef\u7528\u4f5cC \u7a0b\u5e8f\u7684\u65f6\u95f4\u6bd4\u8f83\u3002C51 \u7f16\u8bd1\u5668\u5728_nop_
\u51fd\u6570\u5de5\u4f5c\u671f\u95f4\u4e0d\u4ea7\u751f\u51fd\u6570\u8c03\u7528\uff0c\u5373\u5728\u7a0b\u5e8f\u4e2d\u76f4\u63a5\u6267\u884c\u4e86NOP \u6307\u4ee4\u3002
\u4f8b\uff1a
P()=1;
_nop_();
P()=0;
\u51fd\u6570\u540d\uff1a _testbit_
\u539f \u578b\uff1abit _testbit_(bit x);
\u529f \u80fd\uff1a_testbit_\u4ea7\u751f\u4e00\u4e2aJBC \u6307\u4ee4\uff0c\u8be5\u51fd\u6570\u6d4b\u8bd5\u4e00\u4e2a\u4f4d\uff0c\u5f53\u7f6e\u4f4d\u65f6\u8fd4\u56de1\uff0c\u5426\u5219\u8fd4\u56de0\u3002
\u5982\u679c\u8be5\u4f4d\u7f6e\u4e3a1\uff0c\u5219\u5c06\u8be5\u4f4d\u590d\u4f4d\u4e3a0\u30028051 \u7684JBC \u6307\u4ee4\u5373\u7528\u4f5c\u6b64\u76ee\u7684\u3002
_testbit_\u53ea\u80fd\u7528\u4e8e\u53ef\u76f4\u63a5\u5bfb\u5740\u7684\u4f4d\uff1b\u5728\u8868\u8fbe\u5f0f\u4e2d\u4f7f\u7528\u662f\u4e0d\u5141\u8bb8\u7684\u3002
_cror_ 字符循环右移
_irol_ 整数循环左移
_iror_ 整数循环右移
_lrol_ 长整数循环左移
_lror_ 长整数循环右移
你的这个结果是错的
a = 0xA5A5;
b = _irol_(a,1) ; 执行后 b=0x4b4b;
按照你的结果应给是这样：
a = 0xA5A5;
b = _iror_(a,1) ; 执行后 b=0xd2d2;
PS: _iror_(a,1) 表示把变量a 循环右移1位
既然你懂位移位，你把操作数A5A5和结果转换成二进制就明白了：
A5A5: 1010010110100101
D2D2: 1101001011010010
其中D2D2是操作数a左移1位后得到的结果，末尾补零，最高位的1是标志位。
从结果看，这可是循环右移啊。
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绛旓細C51鍗曠墖鏈虹殑寰幆宸︾Щ鍑芥暟鏄紝_crol_(鍙橀噺鍚嶏紝n)锛屽惊鐜彸绉诲嚱鏁版槸锛宊cror_(鍙橀噺鍚嶏紝n)锛屽嚱鏁颁腑鐨勨滃惊鐜濇槸鎸囧彉閲忕殑8浣嶄簩杩涘埗鏁颁緷娆″悜宸︾Щ涓浣嶏紝鎴栧悜鍙崇Щ涓浣嶃備綘姣斿鐨勶紝鍙8浣嶆暟锛岃1111 1110寰幆宸︾Щ涓浣嶏紝灏辨槸鍦1111 1110銆1111 1101銆1111 1011銆1111 0111銆1110 1111锛岀瓑绛夛紝姣忕Щ浣嶄竴娆★紝...
绛旓細姣斿1010 0100 1010 1100锛屽惊鐜乏绉讳竴浣嶅氨鏄珮浣(绗15浣)绉诲嚭鏀惧埌鏈浣庝綅(绗0浣)锛屽叾瀹冧綅渚濇寰楂樹綅绉诲姩涓浣锛岀粨鏋滄槸0100 1001 0101 1001锛屽惊鐜乏绉讳袱浣嶅氨鍙樻垚浜1001 0010 1011 0010锛岀畻鏈乏绉诲氨鏄Щ鍑哄幓鐨勯珮浣嶄涪澶憋紝渚濇寰鏈浣庝綅琛0锛岀畻鏈乏绉讳竴浣嶇粨鏋滄槸0100 1001 0101 1000锛岀畻鏈乏绉讳袱浣嶆槸...
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绛旓細姹囩紪蹇樿浜 c鐨璇 dat<<1 涓嶆槸姣忕寰幆宸︾Щ锛1浠ｈ〃宸︾Щ1浣嶏紝瓒呭嚭閮ㄥ垎蹇界暐 --- 甯哥敤鐨勫満鍚堬細u8 a;for( u8 i=0,j=0x01; i<8; i++,j<<=1 ){ if( a&j ){ //a鐨勭i浣嶄负1 } } --- 杩愮畻鐨勬椂鍊欎篃甯哥敤鍒 宸︾Щ涓浣 鍙涓嶈秴鍑鸿寖鍥 鐩稿綋浜幟2 ...
绛旓細澧炲姞涓涓叏灞鍙橀噺锛屽皢寰幆甯告暟缁欏彉閲忥紝鍐嶅鍙橀噺鍋宸﹀惊鐜锛屽皢鍙橀噺璧嬪肩粰P0,uchar a,b锛 c;鍦ㄤ富寰幆涓璓0=_crol_(P0,1); //P0鐨鍊煎悜宸﹀惊鐜Щ鍔 淇敼涓 c=_crol_(c,1); //P0鐨勫煎悜宸﹀惊鐜Щ鍔 P0=c;
绛旓細璁炬湁鏁版嵁璇存槑锛歶nsigned char a,b锛涚幇瑕佹妸a寰幆宸︾Щ2浣嶏紝鍙互鐢ㄥ涓嬭鍙ユ瀹屾垚锛歜=a>>(8-2);// 鐢ㄦ潵寰楀埌姝ｅ父宸︾Щ涓㈠け鐨浣嶅拰寰幆绉浣嶅悗鍏舵纭綅缃 a=a<<2; // 宸︾Щ a=a|b;=> a=(a<<2)|(a>>(8-2));...
绛旓細宸﹀惊鐜鏈緛鍑芥暟锛氬嚱鏁板師鍨嬶細unsigned char _crol_(unsigned char a,unsigned char n);鍗曠墖鏈哄乏绉鍑芥暟鐢ㄦ硶锛氫緥濡傦紝P2=0xff锛 P2=_crol_(P2,1);//璇硶鏄鐨锛屼絾杩欐槸娌℃剰涔夌殑锛屽洜涓烘墽琛岀▼搴忓悗P2杩樻槸鍘熷0xff P2=0xfe; P2=_crol_(P2,1);//鎵ц绋嬪簭鍚嶱2=0xfd ...
