I'm creating a program on the Arduino Due which requires an interrupt to fire every 6.5 us. In its basic form, it reads a UART message and outputs an encoder trace. The problem I'm running into is that when the UART message is being read, the 6.5 us interrupt doesn't fire consistently. I suspect that it's because reading UART is generally interrupt driven on the Arduino. Is there a way to read UART without interrupts? I know the size of the UART messages. Could I simply keep peeking into the RHR and read only when a message is received by directly accessing the registers the UART is held in?