TSB81BA3E: TSB81BA3E

Does TI have any PHY's that allow to configure it to send the PHY packets, including the SELF_ID, at S200? We are trying to interface with a device, for some reason, will only look at S200 packets regardless of types.

HI,

Are you using a 1394 beta-only PHY?

Thanks

David

We are using the TSB81BA3E but are trying to interface with a customer's device. They cannot give us much information on it due to security. Actually, they have our unit and trying to get it to work with their equipment. We cannot even get the FireSpy recording from them. But they are convinced that it is because their device only works with S200 - even PHY packets. And OK if we have to do a redesign. If they were 1394 Beta only PHY would that make a difference?

Hi, 

It sounds like this is a S200-Beta only PHY. The TSB81BA3 is an S800 capable PHY and can only communicate at S800 or S400 Beta speeds per the spec to avoid topological bottle-necks. If it is a S200-Beta only PHY, then it will not work with the TSB81BA3.

The PHY packet will be sent using S100 formatted speed with dummy byte added to make it into an effective rate of S100. 

So we need to make sure the PHY packet can be sent at S100 by the S200-Beta only PHY, otherwise this is a spec violation.

If the S200-Beta only PHY supports S100 PHY packet, then you should use TSB41BA3D instead TSB81BA3 as the TSB41BA3D operates per the 1394B-2002 standard at S100B, S200B, or S400B speed.

Thanks

David

Hello David,

Thank you for your reply. Our problem is the device is in violation of the spec. We have no control over that device. It is set in stone. We want to get around it and were told that it has been done before. It seems that the FireSpy gets around it. We were hoping that you have a PHY that we can configure to violate the spec by sending the PHY packets at S200.

Jim

Hi Jim

We need to clarify between the formatted/packet speed and port operating speed.. 

When you say sending the PHY packet at S200, we need to understand if this is the formatted/packet speed or the port operating speed. If they are sending the PHY packets at S100 packet speed with added dummy byte to make it into S200 port operating speed, then we should use TSB41BA3D instead TSB81BA3 as the TSB41BA3D operates per the 1394B-2002 standard at S100B, S200B, or S400B port operating speed while TSB81BA3 only operating at S800B and S400B port operating speed.

If they are sending the PHY packet at S200 packet speed, then we do not have a PHY that can work around this.

Thanks

David