void alt_irq_init ( const void* base )
{
NIOS2_WRITE_IENABLE(0);
alt_irq_cpu_enable_interrupts();
}
/***************************************************************************************
* Main program: exercises various features of the DE2 Media Computer, as a test
* and to provide an example.
* It performs the following:
* 1. tests the SRAM repeatedly
* 2. scrolls some text on the hex displays, which alternates between "dE2" and
* "PASSEd" if there is no SRAM error detected, and "Error" if an error is detected
* 3. flashes the green LEDs. The speed of flasing and scrolling for 2. is controlled
* by timer interrupts
* 4. connects the SW switches to red LEDs
* 5. handles pushbutton interrupts: pushing KEY1 speeds up the scrolling of text,
* pushing KEY2 slows it down, and pushing KEY3 stops the scrolling
* 6. can test the JP1, JP2 expansion ports, if a ribbon cable is installed between them
* 7. echos text received from the JTAG UART (such as text typed in the
* terminal window of the Monitor Program) to the serial port UART, and vice versa
****************************************************************************************/
int main(void)
{
/* Declare volatile pointers to I/O registers (volatile means that IO load
* and store instructions will be used to access these pointer locations,
* instead of regular memory loads and stores)
*/
volatile int * interval_timer_ptr = (int *) INTERVAL_TIMER_BASE;
volatile int * pushbutton_ptr = (int *) PUSHBUTTON_BASE;
/* initialize 7-segment displays buffer (dE2 just before being visible on left side) */
display_buffer[0] = 0xdE2;
display_buffer[1] = 0x0;
display_buffer[2] = 0x0;
green_LED_pattern = 0x55555555; // used for a flashing pattern on the green lights
eight_sec = 0; // initialize 8-second delay counter
display_toggle = 0; // display initialized to scroll the text dE2
shift_direction = 1; // initial shift direction is to the right
*(interval_timer_ptr + 1) = 0x7; // Set START = 1, CONT = 1, ITO = 1
*(pushbutton_ptr + 2) = 0xE; // Set the 3 interrupt mask bits to 1 (bit 0 is Nios II reset)
#if !RIBBON_CABLE_INSTALLED
NIOS2_WRITE_IENABLE( 0x3 ); // Set interrupt mask for the interval timer and pushbuttons
#else
NIOS2_WRITE_IENABLE( 0x3 | 0x1000 ); // also enable expansion port (JP2) interrupts
#endif
NIOS2_WRITE_STATUS( 1 ); // Enable Nios II interrupts
int * SRAM_ptr;
int SRAM_write = 0x55555555;
int SRAM_read;
int memory_error = 0;
while ( !memory_error )
{
SRAM_ptr = (int *) SRAM_BASE;
while( (SRAM_ptr < (int *) SRAM_END) & !memory_error )
{
Update_HEX_display ( display_buffer[1] );
Update_red_LED ( ); // read slider switches and show on red LEDs
Update_UARTs ( ); // update both the JTAG and serial port UARTs
/* only test the Expansion ports if there is a 40-pin ribbon cable connected
between them. */
#if RIBBON_CABLE_INSTALLED
if (!Test_expansion_ports ( ))
{
memory_error = 1; // use this to break out of the while loop
}
#endif
// test SRAM
* SRAM_ptr = SRAM_write;
SRAM_read = * SRAM_ptr;
if (SRAM_read != SRAM_write)
{
memory_error = 1;
}
SRAM_ptr += 1;
};
SRAM_write = ~SRAM_write;
if ( eight_sec > 80 )
{
eight_sec = 0; // restart the 8-second delay counter
if ( display_toggle == 0 )
{
display_toggle = 1;
display_buffer[0] = 0xbA55Ed; // code for the word PASSEd
display_buffer[1] = 0x0;
display_buffer[2] = 0x0;
}
else
{
display_toggle = 0;
display_buffer[0] = 0xdE2; // code for the word dE2
display_buffer[1] = 0x0;
display_buffer[2] = 0x0;
}
}
};
display_buffer[0] = 0xe7787; // code for the word Error
display_buffer[1] = 0x0;
display_buffer[2] = 0x0;
while ( 1 )
{
Update_HEX_display ( display_buffer[1] );
}
return 0;
}
/*
* To initialize the internal interrupt controller, just clear the IENABLE
* register so that all possible IRQs are disabled.
*/
void altera_nios2_qsys_irq_init(void)
{
NIOS2_WRITE_IENABLE(0);
}