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,
|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|