uart interrupt not working

[Altera_Forum]

Hi everyone, 

 I&#39;m using the Altera DE2 board. I am trying to setup a serial link between PC and UART, but UART doesn&#39;t seem to be receiving anything. Here&#39;s the code that I have. Could anyone tell me what&#39;s wrong with it? Thanks. I&#39;m using hyper terminal to send the data and I have jtag_uart mapped as stdin/stdout/stderr to display the char I received through the UART. # include <stdio.h># include "system.h"# include "sys/alt_irq.h"# include "altera_avalon_uart_regs.h" # define RRDY_MSK 0x0080  /* Declare a global variable to hold the uart data value */ unsigned char uart_data;  //ISR for receiving static void IsrRxUart0(void* context, alt_u32 id) {   /* cast the context pointer to an character pointer.*/  unsigned char* uart_data_ptr = (unsigned char*) context;   //if RRDY bit of status register is clear  if((IORD_ALTERA_AVALON_UART_STATUS(UART_0_BASE) & RRDY_MSK) == 0x0000)  {  //IOWR_ALTERA_AVALON_UART_STATUS(UART_0_BASE, 0x0000);  *uart_data_ptr = IORD_ALTERA_AVALON_UART_RXDATA(UART_0_BASE);  }  // enable UART interrupt for read ready (setting IRRDY bit)  IOWR_ALTERA_AVALON_UART_CONTROL(UART_0_BASE, 0x0080); }  /* Initialize the uart */ static void InitUart0() {  /* Recast the uart_data pointer to match the  * alt_irq_register() function prototype.   */  void* uart_data_ptr = (void*) &uart_data;    //enable UART interrupt for read ready (setting IRRDY bit)  IOWR_ALTERA_AVALON_UART_CONTROL(UART_0_BASE, 0x0080);    //register UART receiver ISR  alt_irq_register(UART_0_IRQ, uart_data_ptr, IsrRxUart0);   }   int main() {   InitUart0();  while(1)  {  if(uart_data)  {  printf("This is the character received: %c \n", uart_data);  }  }  return 0; }

[Altera_Forum]

please refer to http://www.niosforum.com/pages/forum.php?cat_id=5 (http://www.niosforum.com/pages/forum.php?cat_id=5) , started by mountain8848!