51单片机如何判断哪个矩阵按钮按下详细解释

1、下图是解释给定P3口的值集合unsigned char code givenP3Table[]={0xfe,0xfd,0xfb,0xf7};给定P3口后按下某个按钮响应的值集合unsigned char code implyP3Table[4][4]= {{0xee,0xde,0xbe,0x7e}, {0xed,0xdd,0xbd,0x7d}, {0xeb,0xdb,0xbb,0x7b}, {0xe7,0xd7,0xb7,0x77}};