UART ISR

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originally posted by rugbybloke@Sep 2 2005, 10:02 AM

if you look in the directory altera\kits\nios2\components\altera_avalon_uart there is a driver for the uart, both interrupt driven and non-interrupt driven. i suspect that your problem is that the uart driver is automatically installed on your system, so it is handling the isr. you will be able to tell by looking in alt_sys_init.c, but you should probably read chapter 4 and 5 of the nios ii software developers handook to understand what alt_sys_init.c is first.

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I have looked into the codes you say,

but i want to use as less as possible nios II API because I want to

understand what I'm doing so I've registered by hand the IRQ

associated to the IRQ mapped to the UART in the Hardware Platform.

As I can read on datasheet i can see that

" The UART core outputs a single IRQ signal to the Avalon interface, which

can connect to any master peripheral in the system, such as a Nios II

processor. The master peripheral must read the status register to

determine the cause of the interrupt.

Every interrupt condition has an associated bit in the status register

and an interrupt-enable bit in the control register. When any of the

interrupt conditions occur, the associated status bit is set to 1 and

remains set until it is explicitly acknowledged. The IRQ output is asserted

when any of the status bits are set while the corresponding interruptenable

bit is 1. A master peripheral can acknowledge the IRQ by clearing

the status register.

At reset, all interrupt-enable bits are set to 0; therefore, the core cannot

assert an IRQ until a master peripheral sets one or more of the interruptenable

bits to 1.

All possible interrupt conditions are listed with their associated status

and control (interrupt-enable) bits in Table 6–5 on page 6–16 and

Table 6–6 on page 6–18. Details of each interrupt condition are provided

in the status bit descriptions. "

so the IRQ should be setted automatically by the CPU and the only think

I have to do is to register the irq to a custom IRQ handler function. There

is an example on the datasheet for the PIOs Peripheral.

I've looked into my alt_sys_init.c and I've found these:

void alt_sys_init( void )

{

ALTERA_AVALON_TIMER_INIT( TIMER, timer );

ALTERA_AVALON_JTAG_UART_INIT( JTAG_UART_0, jtag_uart_0 );

ALTERA_AVALON_SYSID_INIT( SYSID, sysid );

ALTERA_AVALON_CFI_FLASH_INIT( EXT_FLASH, ext_flash );

ALTERA_AVALON_LAN91C111_INIT( LAN91C111, lan91c111 );

ALTERA_AVALON_LCD_16207_INIT( LCD, lcd );

ALTERA_AVALON_UART_INIT( SERIALE_INT, seriale_int );

ALTERA_AVALON_UART_INIT( SERIALE_EXT, seriale_ext );

ALTERA_AVALON_UART_INIT( SERIALE_FUT, seriale_fut );

}

yes I&#39;ve 3 UARTS.... http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/sad.gif ....

now if I recall the API, (but I wish that there is another method) how I have to do ???

there is any kind of example?

shadowice