Clarification of the Hardware Checklist i.MX6

[bomsweigh]

Hello,

We are finishing up the design of an IMX6 and we had a question about the three lines below.  They come from the hardware design checklist. The questions are:

12a. What does a tandem 0Ohm resistor mean?  Tandem to what?

12b Is the SD port clock trace the same as SDx_CLK?

13 From our reading of the errata/apnote, the safest method to accomplish this is to provide an external circuit to power down the SD cards?

14 Do we understand correctly that an in-line zero Ohm resistor is required on all of the SDx_CLK lines between the i.MX and the SD Card?

Thank you for the guidance,

BW

Not Sure	12	Add reserved tandem 0Ω resister in SD port clock trace and place near i.Mx6 side for SI consideration.		CUS
Not Sure	13	Please keep i.Mx6 "SDx_RESET" pin connecting properly with device reset pin  when eMMC/SD fast boot is used in a design. (i.M6DQ AC and i.MX6SDL AB version had fixed this issue, don't need consider this item.) See below need to add I/O line to cycle SD card power.
Not Sure	14	NAND_RE and SDx_CLK are loop back as internal reference clock at internal  pad, recommend adding a series 0hom resister on these two signals and place near i.Mx6 pin side to reduce the potential reflect SI issue.”		CUS

[igorpadykov · Accepted solution]

Hi Boms

12a. 0Ohm resistor is used for testing and bringup purposes, can be removed in final design. 

12b yes

13 usage of SD card "Reset" signal is described in SD specifications.

14 zero Ohm resistor is not required

Best regards

igor

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[bomsweigh]

Thank you very much.