i.MX Processors中的主题 Re: is RSTA reset equivalent to RSTC+RSTD for System control register (SYSCTL) in eSDHCv2 of i.MX257?

is RSTA reset equivalent to RSTC+RSTD for System control register (SYSCTL) in eSDHCv2 of i.MX257?

aldobiziak — Tue, 05 May 2015 08:49:07 GMT

Goodmorning everybody,

from reference manual (i.MX25 Multimedia Applications Processor Reference Manual, Rev. 2), I get the following definitions:

RSDT = Software reset for DAT line. Resets part of the data circuit and the DMA circuit.

RSTC = Software reset for CMD line. Resets part of the command circuit.

RSTA = Software reset for all.

Is RSTA reset equivalent to RSDT plus RSTC reset?

Regards

Aldo

Re: is RSTA reset equivalent to RSTC+RSTD for System control register (SYSCTL) in eSDHCv2 of i.MX257?

Yuri — Tue, 05 May 2015 10:52:32 GMT

In some sense the RSTA is “greater” than (RSTD + RSTC).
The RSTC resets command agent, the RSTD resets data agent, the RSTA
resets all controller. Please look at Figure 23-2 (enhanced Secure Digital Host
Controller (eSDHC) Block Diagram) of the i.MX25 Reference Manual.

Have a great day,
Yuri

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Re: is RSTA reset equivalent to RSTC+RSTD for System control register (SYSCTL) in eSDHCv2 of i.MX257?

aldobiziak — Tue, 05 May 2015 11:59:18 GMT

Thank you for your answer, but I need more information sorry.

What's RSTA do more than RSTD + RSTC ?

Reset all internal buffers of eSDHC? (IP bus IF, internal Dual-Port Buffer RAM)

What about eSDHC clocks and eSDHC interrupt registers?

Additional infomation:

My question was born to fix "ENGcm07207" bug. The recommended work around is to use RSTA reset (see

http://www.freescale.com/docs/pcn_attachments/16200_IMX25CE_Rev7.pdf

)

But, sdhci linux kernel driver uses RSTD + RSTC instead of RSTA.

For that reason I need to know if RSTD + RSTC can fix "ENGcm07207" bug.

Regards

Re: is RSTA reset equivalent to RSTC+RSTD for System control register (SYSCTL) in eSDHCv2 of i.MX257?

Yuri — Tue, 12 May 2015 01:59:22 GMT

This is not mentioned in the i.MX25 Reference Manual, but I found the following

for some devices, based on the similar eSDHC IP :

“Soft reset for data(SYSCTL[RSTD]) should not be issued when SD clock is disabled, that

is, when SYSCTL[SDCLKEN] is cleared. Instead, the host driver may issue soft reset for all

(SYSCTL[RSTA])”. The RSTA should be used for the ENGcm07207.

Regards,

Yuri.