Hands-On RTOS with Microcontrollers

Queue-based driver

First, let's look at how to more efficiently implement the polled driver (previously implemented by polling the UART registers within a task). In this implementation, instead of using a task to repeatedly poll the UART registers, a function will be used to set up the peripheral to use interrupts and initiate the transfer. A complete set of ISR function prototypes can be found in the startup file (for the STM32F767 used in our examples, this file is Chapter_10/startup_stm32f767xx.s).

Each *_IRQHandler instance in startup_stm32f767xx.s is used to map the function name to an address in the interrupt vector table. On ARM Cortex-M0+, -M3, -M4, and -M7 devices, this vector table can be relocated by an offset at runtime. See ...