01-09-2019, 01:00 AM
> 3.3v can be used instead of 1.8v ? If so, 1.8v-regulator do not need.
I understood that the point of your remark is like the above.
(My English understanding is as you are aware)
The following is the view on that premise.
https://forum.pine64.org/showthread.php?...9#pid39379
It is about half a year ago, I tried that condition (3.3v), that is the above post.
It certainly worked.
---
ROCK64 Schematic v 2.0 (Production Release)
http://files.pine64.org/doc/rock64/ROCK6...171019.pdf
Please refer to the pdf "Embed FEPHY" page (11/19) above.
The supply voltage to this FEPHY-block is 1.8v / 1.0v .
As far as the RK3328 data sheet is not available, everything is guessed.
Perhaps the PHY driver/receiver part is designed for use at 1.8v.
If so, termination to 3.3v is risky.
If there is something exceeding the absolute maximum voltage, it will lead to unrecoverable destruction.
I think that their design (terminated to 1.8v) is more reasonable.
Actually, At the termination to 3.3v, ROCK64(RAM=1G) is work.
However, ROCK64(RAM=4G/2G) did not work.
On the other hand, in the case of termination to 1.8v,
All ROCK64(RAM=1/2/4G) work fine.
Regarding the 1.8v-regulator, I described it based on this fact.
Again again, I think that their design (terminated to 1.8v) is reasonable.
*) However, "62Ω" is a mystery. I am the first time to see such a number.
---
It was quite a while ago, I tried changing the voltage at the termination.
and it's experiment data still remained.
According to it, it is sensitive.
x 1.61v ((27|27 ) / 22) : 13/22
o 1.73v ((22|27 ) / 22) : 12/22
o 1.83v ((22|22 ) / 22) : 11/22
o 2.01v ((22|22|47) / 22) : 9/22
x 2.16v ((22|22|22) / 22) : 7/22
----
> I have left that end dangling on my schema, although I was suspicious about it.
In conclusion, either way worked.
If you search, you can find examples of both.
Since it is not possible to obtain the data sheet of RK3328,
It can not be said that which is better.
So, they left their original.
I understood that the point of your remark is like the above.
(My English understanding is as you are aware)
The following is the view on that premise.
https://forum.pine64.org/showthread.php?...9#pid39379
It is about half a year ago, I tried that condition (3.3v), that is the above post.
It certainly worked.
---
ROCK64 Schematic v 2.0 (Production Release)
http://files.pine64.org/doc/rock64/ROCK6...171019.pdf
Please refer to the pdf "Embed FEPHY" page (11/19) above.
The supply voltage to this FEPHY-block is 1.8v / 1.0v .
As far as the RK3328 data sheet is not available, everything is guessed.
Perhaps the PHY driver/receiver part is designed for use at 1.8v.
If so, termination to 3.3v is risky.
If there is something exceeding the absolute maximum voltage, it will lead to unrecoverable destruction.
I think that their design (terminated to 1.8v) is more reasonable.
Actually, At the termination to 3.3v, ROCK64(RAM=1G) is work.
However, ROCK64(RAM=4G/2G) did not work.
On the other hand, in the case of termination to 1.8v,
All ROCK64(RAM=1/2/4G) work fine.
Regarding the 1.8v-regulator, I described it based on this fact.
Again again, I think that their design (terminated to 1.8v) is reasonable.
*) However, "62Ω" is a mystery. I am the first time to see such a number.
---
It was quite a while ago, I tried changing the voltage at the termination.
and it's experiment data still remained.
According to it, it is sensitive.
x 1.61v ((27|27 ) / 22) : 13/22
o 1.73v ((22|27 ) / 22) : 12/22
o 1.83v ((22|22 ) / 22) : 11/22
o 2.01v ((22|22|47) / 22) : 9/22
x 2.16v ((22|22|22) / 22) : 7/22
----
> I have left that end dangling on my schema, although I was suspicious about it.
In conclusion, either way worked.
If you search, you can find examples of both.
Since it is not possible to obtain the data sheet of RK3328,
It can not be said that which is better.
So, they left their original.
