IRQ Controller Driver

Overview

RISC-V CSR Interrupt Management (MIE/MSTATUS).

Usage & Initialization.

Note

This module controls the processor's willingness to accept interrupts. It does not configure the external PLIC, but rather the CPU's internal gates for Software, Timer, and External (PLIC) interrupts.

To enable IRQ for external interrupt:

• Please refer to UART Interrupt Demo.

  irq_setTrapVector(trap_entry);
  irq_setType(IRQ_EXTERNAL);
  irq_enable();

To enable IRQ for Timer interrupt:

• Please refer to User Timer Demo.

  irq_setTrapVector(trap_entry);
  irq_setType(IRQ_TIMER);
  irq_enable();

To enable IRQ for Software interrupt:

• Please refer to CLINT Timer Interrupt Demo.

  irq_setTrapVector(trap_entry);
  irq_setType(IRQ_SOFTWARE);
  irq_enable();

To register a custom IRQ Handler:

• Use irq_registerExt to register a custom handler for a specific PLIC interrupt source.

  int custom_IRQ_handler()
  {
   if (uart_readStatus(&uart0) & 0x00000200){
          //Entering uart rx fifo not empty interrupt routine
          uart_writeStatus(&uart0,uart_readStatus(&uart0) & 0xFFFFFFFD);
          uart_write(&uart0, uart_read(&uart0));
          uart_writeStatus(&uart0,uart_readStatus(&uart0) | 0x02);
          return 1;
      }
      return 0;
  }
   
  void main() {
      irq_registerExt(SYSTEM_UART_0_IO_INTERRUPT, custom_IRQ_handler);
      irq_setTrapVector(trap_entry);
      irq_setType(IRQ_EXTERNAL);
      irq_enable();
      uart_setRxInterruptEnable(&uart0, 0x1U);
  }

Topics
	API Functions
	Function definitions for IRQ driver.
	Data Structures
	Structs and Enums used by the driver.