For this design, the UART is the only peripheral that uses interrupts. When the UART bus receives new data, an interrupt triggers. This interrupt-driven approach frees the processor from constantly monitoring the UART, allowing it to focus on external peripherals when no UART data is present.
The MicroBlaze-V processor has two primary tasks. First, it continuously monitors the state of input peripheral devices and forwards any changes to the web console via the UART. Second, it updates the state of the output devices when a message is received from the web console.
For the outputs, an update occurs only when a new message is received over the UART via an interrupt, so the scheduler does not manage this task. In contrast, the inputs do no use interrupts. Instead, the processor constantly polls the state of each device to detect changes. The task scheduler integrates the reading of input device statuses, allowing for a modular approach that simplifies adding new peripherals to the design. Some peripherals can be polled at any frequency, while others require a delay between queries. A timer is used to ensure that each peripheral is queried at the appropriate interval.