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Altera_Forum's avatar
Altera_Forum
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12 years ago

Assembly or C program that produce an output tone on speaker NIOS II.

All i want to do is produce and output tone to the speaker. My university has a sample code http://www-ug.eecg.toronto.edu/msl/nios_devices/dev_audio.html However for some reason...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

I want to produce a tone output on the speakers 


Assembly Example: Echo program - connects mic to speakers, polling
.equ ADDR_AUDIODACFIFO, 0x10003040
main:
  movia r2,ADDR_AUDIODACFIFO
  ldwio r3,4(r2)      /* Read fifospace register */
  andi  r3,r3,0xff    /* Extract#  of samples in Input Right Channel FIFO */
  beq   r3,r0,main  /* If no samples in FIFO, go back to start */
  ldwio r3,8(r2)
  stwio r3,8(r2)      /* Echo to left channel */
  ldwio r3,12(r2)
  stwio r3,12(r2)     /* Echo to right channel */
  br main

This code was provided by my university website(http://www-ug.eecg.toronto.edu/msl/nios_devices/dev_audio.html), however its broken and the output is scrambled noise nothing is right. How can I output to the speaker a single tone?