多次按下PIC16F877中的开关按钮

Question

我在PIC16F877上工作

我想澄清一件事。有我们的董事会配置：

这是家庭作业，所以你不能帮助我，只提示:)。所以任务说我必须按 SW00 按钮开始，然后推 SW04 ， SW05 ， SW06 ， SW07 用于校准LED中的数字，然后按 SW11 完成。有两件事让我担心：

1.How to check if button is pressed because I only check RB4,RB5,RB6,RB7 bits, 
  so I can't distinguish for example SW00 and SW04 buttons(RB4). 
  And also it is said that:"In your development boards RB4 pin 
  is connected to RC2 pin. Therefore you have to  configure RB4 and RC2 properly
   for correct operation of buttons."

2.These buttons are not Schmidt-triggered, so I can use TIMER0, can you light up 
  about this stuff.

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