c programming for Pin pio

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originally posted by niceguylow@Dec 7 2005, 02:56 PM

hi there...i'm currently having problem of understanding the pin input pio....

my nios is connected to the 16 bits pio pin in the development board...how to write a c code to retrieve the inputs from this pio..

since this inputs are in binary, do i need to convert to decimal or the system itself will convert for me in c language.

thnaks and regards

wayne

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You can try using the PIO functions made available by Altera... like the one used in the count_binary example of the HAL...

The numbers you&#39;ll read from the PIO have to be interpreted as a set of bits inside a 32-bit integer... For example, if you have a 2 bit PIO, you&#39;ll end up having the 2 bits valies inside the 2 less significant bits of the integer you read from the peripheral.

bye

Paolo

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originally posted by paolo.gai+dec 7 2005, 08:38 am--><div class='quotetop'>quote (paolo.gai @ dec 7 2005, 08:38 am)</div>

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<!--quotebegin-niceguylow@Dec 7 2005, 02:56 PM

hi there...i&#39;m currently having problem of understanding the pin input pio....

my nios is connected to the 16 bits pio pin in the development board...how to write a c code to retrieve the inputs from this pio..

since this inputs are in binary, do i need to convert to decimal or the system itself will convert for me in c language.

thnaks and regards

wayne

<div align='right'><{post_snapback}> (index.php?act=findpost&pid=11393)

--- quote end ---

--- Quote End ---

You can try using the PIO functions made available by Altera... like the one used in the count_binary example of the HAL...

The numbers you&#39;ll read from the PIO have to be interpreted as a set of bits inside a 32-bit integer... For example, if you have a 2 bit PIO, you&#39;ll end up having the 2 bits valies inside the 2 less significant bits of the integer you read from the peripheral.

bye

Paolo

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[/b]

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this is my sample of the c ....will it work ?

let say my pio is a 16 bit input...would it put receive the 16 bits input.

since np_pio is defined as int...the 16 bits are automatically converted into integer?

np_pio *pio = na_pio;

if i want to access obtain the data...

pio->np_piodata;

Are you using IORD_ALTERA_AVALON_PIO_DATA(base) ?

Paolo

Hello niceguylow,

the PIO Core is described in the Quartus II Development Software Handbook Volume 5: Embedded Peripherals (http://www.altera.com/literature/quartus2/lit-qts-peripherals.jsp). For accesing the PIO registers there are some macros which are included in “altera_avalon_pio_regs.h”:

#define IOADDR_ALTERA_AVALON_PIO_DATA(base)           __IO_CALC_ADDRESS_NATIVE(base, 0)# define IORD_ALTERA_AVALON_PIO_DATA(base)             IORD(base, 0) # define IOWR_ALTERA_AVALON_PIO_DATA(base, data)       IOWR(base, 0, data)
# define IOADDR_ALTERA_AVALON_PIO_DIRECTION(base)      __IO_CALC_ADDRESS_NATIVE(base, 1)# define IORD_ALTERA_AVALON_PIO_DIRECTION(base)        IORD(base, 1) # define IOWR_ALTERA_AVALON_PIO_DIRECTION(base, data)  IOWR(base, 1, data)
# define IOADDR_ALTERA_AVALON_PIO_IRQ_MASK(base)       __IO_CALC_ADDRESS_NATIVE(base, 2)# define IORD_ALTERA_AVALON_PIO_IRQ_MASK(base)         IORD(base, 2) # define IOWR_ALTERA_AVALON_PIO_IRQ_MASK(base, data)   IOWR(base, 2, data)
# define IOADDR_ALTERA_AVALON_PIO_EDGE_CAP(base)       __IO_CALC_ADDRESS_NATIVE(base, 3)# define IORD_ALTERA_AVALON_PIO_EDGE_CAP(base)         IORD(base, 3) # define IOWR_ALTERA_AVALON_PIO_EDGE_CAP(base, data)   IOWR(base, 3, data)

Regards,

niosIIuser

.......

alt_16 my_data;

.....

my_data = IORD(YOUR_PIO_BASE_ADDRESS,0);

......