分组引脚不会全部触发中断吗？

我目前正在做一些事情，需要将多个输入的状态发送给一个超过I2C的ARDUINO。
理想情况下，我希望每个端口都有一个单独的中断，但是由于我需要在设计中使用PSoC4，所以我不能这么做。（遗憾的是，如果需要比端口更多的中断，就不能将单个引脚路由到中断组件）。
到目前为止，我已经设置了系统，使得一组8个引脚有一个附加的中断，并且每当有变化时，中断就在I2C上发送按钮的状态，以及允许ARDUINO识别哪个按钮被按下的信息。
但是，组中按钮0的状态改变不会触发中断！发生了什么事？如果我通过按下另一个按钮来触发中断，而0被按下，则0的状态被发送到主单元：



     以下为原文
  I am currently working on something which requires the state of several inputs to be sent to an arduino over I2C.

Ideally I would like to have a separate interrupt for each port but due to the fact that I need to use PSOC4's in the design I can't do this.
(shame you can't route individual pins to interrupt components if you need more interrupts than ports)

So far I have the system set up so that a group of 8 pins has an interrupt attached and the interrupt sends the state of the button over I2C whenever there is a change, along with information allowing the arduino to identify which button was pressed.

HOWEVER
A change of state on button 0 of the group won't trigger an interrupt! What is going on?
If I trigger the interrupt by pressing another button whilst 0 is held down the state of 0 is sent to the main unit just fine :S