OMAP-L138, McASP and FIFO functionalities

Arthur Cartier

Other Parts Discussed in Thread: OMAP-L138

Hello,

I'm trying to make an audio loop-back on our experimentation board, and I'm trying to make it work with our scheduler, unfortunately after few packets, a transmit underrun is raised, I think it's because sometimes a McASP interruption is delayed by a timer interruption with an higher priority used by our scheduler.

So I would like to use the FIFO feature of the OMAP-L138, but I can't find where I should wright data and where I can read data from the FIFO buffer.

Thank you in advance for any help you may provide me.

Arthur CARTIER

over 13 years ago

0 Rahul Prabhu over 13 years ago

TI__Guru** 116170 points

Arthur,

You might find this post useful to read/write to McASP AFIFO

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/193923.aspx

I believe the address your looking for is (0x01D0 2000) which is provided in the datasheet as McASP 0 Data (size 4K) in table 2-4. This is also refered to as start address of RBUF/XBUF in table 5-52 in case you are using EDMA.

Regards,

Rahul

0 Arthur Cartier over 13 years ago in reply to Rahul Prabhu

Intellectual 410 points

Rahul,

Thank you for your help.

Even if I don't want to use EDMA but only the FIFO feature, I think the address you give me is exactly what I need.

But can you give me the reference of the data sheet, I have only found the McASP user guides where their is no table 2-4 or 5-52.

Cordially

Arthur CARTIER

0 Rahul Prabhu over 13 years ago in reply to Arthur Cartier

TI__Guru** 116170 points

Arthur,

Here is the link to the datasheet in which you will find the Table 2-4 and table 5-52 that I was refering to:

http://www.ti.com/lit/ds/symlink/omap-l138.pdf

Regards,

Rahul

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OMAP-L138, McASP and FIFO functionalities