About Variable_Output_Data_Window of SD specification in i.MX6 series.

[keitanagashima]

Dear Sir or Madam,

Hello.

I have a question about Variable_Output_Data_Window of SD specification in i.MX6 series.

Refer to Frequency_Range_Consideration in SD specification Phsical Layer Specification V4.20.

Is MX supporting Variable_Output_Data_Window function?

[Q1]

There is description of "SDR-104" in data sheet and Reference manual.

There is not a specification like tODLY in SDR104 and it is automatically adjusted by Variable-delay function(CMD19).

Is i.MX6S/DL/D/Q supporting this feature?

And is it supporting both of SDR-104 and SDR-50?

[Q2]

In SDR104, is it automatically adjusted at the case of Write operation, too?

Best Regards,

12-Nov-2014

Keita

[igorpadykov · Accepted solution]

Hi Keita

1. instead tODLY there is tOD in

Table 56. SDR50/SDR104 Interface Timing Specification IMX6DQCEC

CMD19 is supported for SDR-104.

2. yes, there is special uSDHC DLL for such purpose, please check

sect.67.5.3.2.4 DLL (Delay Line) in Read Path IMX6DQRM

Best regards

igor

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[keitanagashima]

Hi Igor,

>2. yes, there is special uSDHC DLL for such purpose, please check

>sect.67.5.3.2.4 DLL (Delay Line) in Read Path IMX6DQRM

Is this delay function support to write operation, too?

I haven't found the description in write path.

Best Regards,

Keita

[igorpadykov]

Hi Keita

seems you are right:

delay function supports only read operation.

Best regards

igor

[keitanagashima]

Hi Igor,

Hello.

[Description from "SD Physical Layer Specification 4.10"]

- Variable Output Data Window is supported in SDR104.

- At the initialization step the host should take care to find the optimal sampling point for the card output.

Let me clarify my understanding again. (It's important point.)

Is Variable_Output_Data_Window function support in i.MX6 only read operation?

In write operation, i.MX6 doesn't support this function, isn't it?

BR,

Keita

[igorpadykov]

Hi Keita

I think "SD Physical Layer Specification 4.10" is not supported:

only 3.0 supported according to sect.67.1.1 Features IMX6DQRM

The features of the uSDHC module include the following:

• Conforms to the SD Host Controller Standard Specification version 3.0

Best regards

igor

[keitanagashima]

Hi Igor,

• Conforms to the SD Host Controller Standard Specification version 3.0

My customer found the same description on v3.0.

Best Regards,

Keita

[igorpadykov]

Hi Keita

please provide reference to this document and

page where it is described.

Best regards

igor

[keitanagashima]

Hi Igor,

Please refer to "6.7.3.3.3Output Timing of Variable Window(SDR104 up to 208MHz) [page.161]" and "6.7.3.3.1Frequency Range Consideration [page.161]" in Physical Layer Specification v3.0.

BR,

Keita

[igorpadykov]

Hi Keita

these chapters are for SD card output,

not for i.MX6 uSDHC module output.

SD 3.0 specification does not provide such requirements for Host.

In your original question:

"Is MX supporting Variable_Output_Data_Window function?"

- this seems refered to i.MX6 uSDHC module output.

Best regards

igor

[keitanagashima]

Hi Igor,

>SD 3.0 specification does not provide such requirements for Host.

I will send you the mentioned point.

Please check it again.

BR,

Keita

[keitanagashima]

Hi Igor,

Thank you for your reply.

Let me clarify it again.

Refer to Note.1 of Table 58. SDR50/SDR104Interface Timing Specification in IMX6SDLAEC(Rev.3).

There is description of "Data window in SDR100 mode is variable".

Is it support Variable_Output_Data_Window function in i.MX6 series of SDR50/104?

Best Regards,

Keita

[igorpadykov]

Hi Keita

yes it supports.

Best regards

igor