Why use about Debug LED and SDXC Power Control Inverter? - I.MX6DL(Automotive)

[inhojeon]

Hi all,

I wondering about 'Debug LED and SDXC Power Control Inverter'  of I.MX6DL(Automotive) SABRE Bd Circuit.

And I wondering about what purpose of 'SDa_RST_B'  and 'SDa_PWROFF' , 'USER_LED', 'P3V3_SDa_SWITCHED'

And, Is 'Debug LED and SDXC Power Control Inverter' circuit must to use?

Best Regards,

Inho Jeon. 

[inhojeon]

Hi, Yuri!

I have a question about "SDa (SD3) power source for MX6 I/O. Required for SDXC USH-1 I/O logic level change " of i.MX6DL(Automotive) that refer to SABRE BD Schematics( 6 of 22 pages).

I want to NVCC_SD3 is P1V8GEN4 for SDXC(high speed SD IO level 1.8V).

So, I'll designed just R613 & R640 for NVCC_SD3 level control by add & del R640,R631 without U508(ADG849) and SDa_VSELECT(SD3_VSEL_GPIO_18),  Is it right way?

Plaese, Infome me that questions, ASPA.

Best Regards,

Inho Jeon.

[Yuri]

Hello,

  To get P1V8GEN4 for SDXC : populate R631, assuming R640 is removed, U508 is not needed. 

Have a great day,
Yuri

[inhojeon]

Hi, Yuri!

Thank you for your reply.

You mean just need to parts of R640 & R631 for driving SD or SDXC memory cards, no need to  parts of 'U508' ,'R633', 'C625',R638 and net of 'SDa_VSELECT(SD3_VSEL_GPIO_18)', is that right?

Best regards,

Inho Jeon

[Yuri]

Yes, just direct connection for corresponding power rail.

~yuri.

[Yuri]

Hello,

1.
Dedug LED is separate scheme, that – generally has no any concern to SDXC support.

2.

  For the SDXC card support it is required to apply 1.8V supply voltage.

GPIO_18 (ALT2: VSELECT of usdhc3) is used to control the NVCC_SD3 for 3.3V and 1.8V voltage select.
SD3_RST(inverted to SDa_PWROFF) is used to control / switch the SD Card Power (P3V3_SDa_SWITCHED).

Have a great day,
Yuri

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[inhojeon]

Hi Yuri,

Thank you for your reply.

You mean if not use SDXC it is not necessary, is that right?

And, if not use SDXC, how to design about  "SDa_RST_B(SD3_RST)" , "P3V3_SDa_SWITCHED" ?

Best Regards,

Inho Jeon

[Yuri · Accepted solution]

Hello,

  If Your design is not intended to use both voltages 3.3V and 1.8 V for SD 
interface and SD supply will not be switched on / off  - the mentioned solution
with switched supply may be ommited.  In such case You may use P3V3_DELAYED
instead of P3V3_SDa_SWITCHED.

Regards,

Yuri.