TMS320F28377D: The sdfm module Ierror when start the dma access

Hello,
I am writing to let you know that a C2000 team member has been assigned to this post and should be answering shortly.

Regards
Baskaran

further more if i didn't write or read data from emif2(the emif2 is connected to an Dual-Port Static RAM) there is no the IFH or IFL error.
The Delta-Sigma Modulation module is AMC1204. The clock is provided by an clock chip(CDCLVC1102PW).
why read or write Dual-port static ram will affect the sdfm's compare module(In my program i used 8 chanel SDFM filter but only effect the sdmf2.ch1 and sdfm2.ch2).
thank you
regards
shook

Shook,

EMIF and SDFM don't belong to same peripheral frame. So, there shouldn't be any conflict to begin with.

I would see whether there any other external interaction in your system which is coupling as a noise on SDFM clock and data pins. Try monitoring your SD_Cx and SD-Dx pins when using EMIF. Also, check whether any of the EMIF and SD-Cx / SD-Dx traces close leading to noise coupling.

Regards,

Manoj

hi

manoj

yes, i consider this error is because the nois,but i monitor the sd-cx and sd-dx signal use oscilloscope,ididn't see the noise on the sd-cx and sd-dx pins.

11.xls

this is the data from the oscilloscope.

the yellow signal is sd-cx, green signal is sd-dx, purple signal is an gpio signal, in my control period (100us), every period i check the error, when the error is happend this gpio will toggle.

1, in the figure i didn't see  the noise so the error isn't because  the noise?

2, before 100us when the gpio toggled, the sd-dx signal's period is more than sd-cx period. this will cause the error?

3, why the sd-dx signal's period will large than the sd-cx signal?

thank you

regards

shook

Shook,

What SDFM mode are you using? I still believe this SDFM comparator issue might be noise related to SD-Cx / SD-Cx signals. Noise on SD-Cx / SD-Dx on few clock (or) data pulse is enough to trigger a false comparator event.

What is your SDFM COSR setting?

Regards,
Manoj

Manoj

The sdfm mode is mode0, the comparator cosr is 32,filtertype is sinc3(changed to sin2 and changed the compare high limit and low limit there is the error also ) , the filter module cosr is 256,filtertype is sinc3.

the figure below is my pcb layout 

if the emif‘s noise coupled to the sd-cx or sd-dx clock,why only sdfm2-chanel1 has the IFH or IFL error?

thank you

regards

shook

hi! manoj
I have resolved this issue.
Set the sd-cx and sd-dx pins internal pullup, then the error disappeared.
why? can you give me some explanation?
thank you
regards
shook

Shook,

Its possible enabling internal pull-up on SD-Cx and SD-Dx pin is helping in noise immunity. Did you already try providing external pull-up on these pins? I wouldn't rely on internal pull as it provides a very weak pull-up.

Regards,
Manoj

manoj
thank you for your answer, i didn't provide the external pull-up on these pins, you said the internal pull-up is a weak pll-up, can you tell me the resistance value of the internal pull-up
thank you
regards
shook

Its around 22KOhms.

Regards,

Manoj

yes，manoj
thank you