AM5728 MCASP1

本帖最后由 一只耳朵怪 于 2018-6-5 14:57 编辑

hi,I want to know if there are some demo about how to use the AM5728`s mcasp1 or mcasp2?

And now I had forrowed the guide and step by step for interfacing an audio DAC to the McASP on AM728 devices. and run ok.
Sitara Linux Software Developer's Guide  →  Sitara Linux SDK  →  Audio: DAC Example
http://processors.wiki.ti.com/index.php?title=Sitara_Linux_Audio_DAC_Example&keyMatch=mcasp&tisearch=Search-EN
but when I try to use the MCASP1 or MCASP2 to transmit some data(not audio data,just usual pcm data). I found there some problem block me.
my step is:
1、follow the guide finish the dummy audio driver.
2、use the alsa-lib/test/pcm_min  to transmit some data. the code as follow:

(figure 1)
3、then use the LA5061 Logic Analyzer to catch the output, as the following:

(figure 2)
the analyzer conectting and setting is:
channel0: DATA
channel14:FRAME
channel15:ACLK
now, my puzzle is:
1、look at the figuer 2.
why the DATA output is 0x0001 0x0001 0x0201 0x0201 0x0401 0x0401...?
and i used "omapconf dump mcasp1" when running ./pcm_min , the reg. value as figuer 3.

2、why the channel 1 and channel 5 have signal output?
3、how to transmit the data using all of the 16 channels of the McASP1? if there are some demo or user guide for me.
thanks.