I am trying to make it so that an interrupt is triggered when data is received through the UART on the TivaLaunchpad without using TivaWare.
- I've set breakpoints in the interrupt handler to verify an interrupt was triggered, the software never stopped at this breakpoint. (Code below)
- I've tried implementing busy-wait to receive just to make sure there was nothing wrong with the rest of my code (e.g. UART setup...). Breakpoints in the busy wait loop stopped at the right line and confirmed I was receiving the right info
- The problem happens to be with how I set up the interrupts for UART
- This is the UART setup code. The 'third paragraph' in the UART_Init() method sets it up for interrupts. This is the part I've most probably got wrong.
````
void UART_Init(void) {
//Enable UART and GPIO cloks for UART 0
SYSCTL->RCGCUART |= (1<<0);
SYSCTL->RCGCGPIO |= (1<<0);
//Disable the UART
UART0->CTL &= ~(1<<0);
//Set the baud rate
UART0->IBRD = 104;
UART0->FBRD = 11;
//Configure LCRH register
UART0->LCRH = 0x00000070;
//Configure for interrupts
UART0->ICR |= (1<<4);
UART0->IM |= (1<<4);
//Priority of 4 for UART0_Handler (IRQ = 5)
NVIC_SetPriority(UART0_IRQn,5);
//Enable interrupts for UART 0
NVIC_EnableIRQ(UART0_IRQn);
//Reenable UART0
UART0->CTL = (1<<0)|(1<<8)|(1<<9);
//GPIOA
GPIOA->DEN |= (1<<0)|(1<<1);
GPIOA->AFSEL |= (1<<1)|(1<<0);
GPIOA->PCTL = (1<<0)|(1<<4);
GPIOA->AMSEL &= ~((1<<0)|(1<<1));
}
````
- This is the ISR for this interrupt:
````
int a;
void UART0_Handler(void) {
UART0->ICR |= (1<<4);
//Line of random code to set a breakpoint to verify it is being executed
a = 4;
}
````
- This is the main function :
I enable the `testCharacter = UART_InChar();` line to activate busy-wait.
````
int main(void)
{
setup();
while(1) {
//Activate line to enable busy-wait
//testCharacter = UART_InChar();
}
}
````
- And the busy-wait routine:
````
unsigned char UART_InChar(void) {
while((UART0->FR&0x0010) != 0);
return (unsigned char)(UART0->DR&0xFF);
}
````
- Using Keil uVision 4
- I've searched for solutions online, but only found questions related to TivaWare, which I'm not familiar with and prefer avoiding.
