Modify the solution of question 1 to have a down/up counter as follows: · RA2= 0 Counter is disabled. · RA2= 1 Counter is enabled: o If there is negative edge signal at pin RA3 then counter counts up. o If there is negative edge signal at pin

//比较器的工作模式：CM2－CM0＝011,交流信号经半波整流送至C1的负端RA1， //参考电压模块产生一个0.63V的电压输出到C1的正端RA2，C1的输出为引脚RA5。 -//Comparator mode: CM2-CM0 = 011, the half-wave rectified AC signal to the negative terminal of C1 RA1,// ​ ​ 0.63V voltage reference module gener