communicate uart with VB

Altera_Forum · ‎12-09-2005

sorry, my english is poor.

I transmit a wavfile to Nios II within MSCOMM32.OCX

baud rate=115200 bps

data bit=8

parity bit=none

stop bit=1

RECEIVER in Nios II IDE

  alt_16 buf;
  for(i=0;i<160;i++){
      fread(&buf, sizeof(alt_16), 1, uart);    //read data from file
      
      if(buf==0x4F4B) break;    //"OK"
      
      IOWR(USER_RAM_BASE, i, buf);    //write data to RAM and play sound
  }

My transmitter transmit data to receiver, but receiver get only incomplete data.

eg. I transmit 0x2353, 0x6411, 0x4235, receiver get only 0x2353, 0x6435, etc.

I guess that transmit speed too fast and transmit buffer too small.

But I can't how to solve it.

thx

Orz

Altera_Forum · ‎12-22-2005

if the uart buffer is overloaded then data will get lost.

you should implement some handsahe between reciver and transmitter

the buffer i'm using is 64bytes so the transmiter will not send more then 64 bytes until the reciver didn't signal that it can read more bytes