Dear sir,
We found some UHS card cannot work in SDR104 on imx8-evk. Sometimes tuning failed, sometimes not command response from card after tuing. All card work OK in high speed mode. We want to know your UHS card test results on imx8-evk.
Below information is from TI for your reference. Do you have similar testing information to share?
http://processors.wiki.ti.com/index.php/Linux_Core_MMC/SD_User%27s_Guide#Testing_Information
FUNCTIONAL UHS CARDS |
---|
STRONTIUM NITRO 466x UHS CARD |
SANDISK EXTREME UHS CARD |
SANDISK ULTRA UHS CARD |
SAMSUNG EVO+ UHS CARD |
SAMSUNG EVO UHS CARD |
KINGSTON UHS CARD (DDR mode) |
TRANSCEND PREMIUM 400X UHS CARD (Non fatal error and then it re-enumerates in UHS mode) |
FUNCTIONAL (WITH LIMITED CAPABILITY) UHS CARD |
---|
SONY UHS CARD - Voltage switching fails and enumerates in high speed |
GSKILL UHS CARD - Voltage switching fails and enumerates in high speed |
PATRIOT 8G UHS CARD - Voltage switching fails and enumerates in high speed |
Best regards,
Miles
Hi Miles
unfortunately I am not aware of such testing informatio, however
tuning failures usually are caused by signal integrity, which may be improved
by adjusting drive strength, for example using sect.8.2.4.192 SW_PAD_CTL_PAD_SD1_
DATA0 SW PAD Control Register (IOMUXC_SW_PAD_CTL_PAD_SD1_DATA0)
i.MX8MDQ Reference Manual
https://www.nxp.com/docs/en/reference-manual/IMX8MDQLQRM.pdf
Note SD drive strength also can be changed, it is described in sect.6.7 Driver Strength
and Bus Timing for 1.8V Signaling SD 3.0 Physical Layer Specification.
Best regards
igor
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Thanks,
Current configurations as below:
IOMUXC_SW_PAD_CTL_PAD_SD2_CLK = 0x87
IOMUXC_SW_PAD_CTL_PAD_SD2_CMD = 0xc7
IOMUXC_SW_PAD_CTL_PAD_SD2_DATA0-4 = 0xc7
current limit = 800mA
driver strength = TypeB (default)
Is it OK?
settings may depend on used sd card, suggest to check waveforms and signal timings
with oscilloscope with each card and adjust iomux settings accordingly.
Best regards
igor