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Altera_Forum
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20 years ago

Problem with DMA in new NIOS

Hello! I've made design for my custom board and I run it does work, but when I added to my design DMA it doesn't work. Then I remove dma from design it again does work. In old ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Hello Camelot,

Did you read the errata „errata.htm“? I had the same problem (http://www.niosforum.com/forum/index.php?act=st&f=17&t=1630) and found the solution there.

DMA HAL routine results in illegal bus condition (SPR 176819)

The Nios II DMA HAL routine results in illegal bus condition if:

- the bursting DMA is connected to slaves wider than 32-bits or

- the "word" checkbox on the Advanced tab in the GUI is unchecked or

- the DMA master is connected only to slaves of data width less than or equal to 16 bits

Workaround: Use a "freestanding" Nios II application to avoid using the HAL, and don't call the DMA init routine for the DMA in question.