DS125MB203: Can DS125MB302 be used to switch two Hosts?

user4779049

Expert 2345 points

Part Number: DS125MB203
Other Parts Discussed in Thread: DS100MB203, USB2ANY

Hi Team,

Please advise me on a question bellow.

Question: Can DS125MB203 be used to switch two hosts shearing one drive?.

Host #1 -----------| DS125MB203| --------------- Drive

Host # 2 ----------| |

The Figure 10 on the Datasheet shows an example of opposite case like bellow

Host #1 -----------| DS125MB203| --------------- Drive #1

| | ----------------- Drive #2

I want to post this question to confirm it.

Mita

over 4 years ago

0 Nasser Mohammadi over 4 years ago

TI__Guru* 93670 points

Hi Mita-San,

Yes this is possible. Device does not haveSASSata app note.pdfe the intelligence to realize which side is the host or the drive.

Please note when using DS125MB203 for this application, there are some guidelines for interfacing to drives. I have attached a copy of this app note to this case.

Regards,, Nasser

0 user4779049 over 4 years ago in reply to Nasser Mohammadi

Expert 2345 points

Nasser-san,

Thank you for the answer.

Mita

0 K.Yaita over 4 years ago in reply to user4779049

Guru 29720 points

Hi Nasser-san,

Thank you always for your support.
I am Mita-san's colleague.

My customer wants to use DS125MB203 or DS100MB203 with pin mode.
He doesn't want to use SMBus mode (host / slave).

According to application note you attached, I believe using pin mode isn't recommended for SATA application.
Is my understanding correct?

Best Regards,
Yaita

0 Nasser Mohammadi over 4 years ago in reply to K.Yaita

TI__Guru* 93670 points

Hi Yaita-San,

SMBus access would provide us more flexibility. This would enable us to fine tune registers - if needed. I strongly suggest using SMBus interface. During product development, they can fine tune registers settings - using SMBus - and then use EEPROM to update the registers. For this, all they need is to put a 3-pins header on their board for SMBus interfacee to a USB2ANY box to setup the registers. Then burn EEPROM with settings and there will not be any SMBus controller/interface.

Regards,, Nasser

0 K.Yaita over 4 years ago in reply to Nasser Mohammadi

Guru 29720 points

Hi Nasser-san,

Sorry to late reply.

I believe EEPROM only takes a subset of the SMBus register bits and we can't access all the registers that are related to Signal Detect and DC Offset disable.
So I believe SMBus slave mode is recommended than EEPROM mode.
Is my understanding correct?

Best Regards,
Yaita

0 Nasser Mohammadi over 4 years ago in reply to K.Yaita

TI__Guru* 93670 points

Hi Yaita-San,

Yes SMBus interface mode provides more fleaxibility and allows access to all registers.

Regards,, Nasser

0 user4779049 over 4 years ago in reply to Nasser Mohammadi

Expert 2345 points

Nasser-san,

Thank you for the answer.

I can cleared it.

Mita

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DS125MB203: Can DS125MB302 be used to switch two Hosts?