基于华邦W90P710开发板的键盘文件，可利用评估板键盘改变值-Keyboard file of Winbond W90P710 development board, you can use the evaluation board to the keyboard to change the value

. Assume the argument x is reduced to y1+y2 = x-kpi 2 in [-pi 2 , +pi 2], and let n = k mod 4.