Access serial port for data sent from Nios II's uart for real time plotting graph in

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How are you UART? are you polling or using interrupts?

I recommend using interrupts: look at the following thread - the code provided in this thread works well... http://www.alteraforum.com/forum/showthread.php?t=17224

I've used this code to communicate with a visual c++ program on the pc.

I think the matlab code for accessing the serial port is correct, so the problem is probably on the FPGA side.

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Hi Krasner,

Thanks for your reply. I dont understand why it is not working, must it be done with interrupts? Couldn't it be done by using iowr on the uart?

I used the following code to access the UART (rs232 serial port) component I created in Qsys, I connected the txdata pin to the oscilloscope and it shows nothing, i am wondering why couldn't I use IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE, txdata); to transmit data to UART?

What I want to do is Nios processor reads data from FPGA, Nios transmits the data to serial port and plot graph real time using Maltab,using de0 nano. I do not need to read data from serial port.

#include "altera_avalon_uart_regs.h"

#define UART_BASE 0x00002000

int main (void)

{alt_u16 status, rxdata=0,aa=0, txdata=0;

while (! (status & 0x0040)) // Wait for transmission completion

status = IORD_ALTERA_AVALON_UART_STATUS (UART_BASE);

printf("status= %.2f V \r\n", (float) status);

rxdata = 5; // assuming I get this data by accessing sdram in Nios

txdata = rxdata;

IOWR_ALTERA_AVALON_UART_TXDATA(UART_BASE, txdata);

printf("txdata= %.2f V \r\n", (float) txdata);

return 0;}

Could you please give me some hints? Thanks