[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: SV: [bluetooth-dev] Clock for PCM




Preamble: 
The issues discussed here are sligthly off topic, since they are not
directly related to the AXIS stack. But I think, the problems are of general
interest.



> I just got the answer on that same question today:
> 
> When the Ericsson module is set as a PCM master it will send the PCM clock.
> But not the entire time, only close to when the PCM synch signal is send
> out.


Henrik,

Thanks for the answer. I'm working together with Sascha, who wrote the
original posting about this and the SCO issues.

Actually, we didn't observe any clock or signal changes on any pin of the
PCM I/F. It looked like if the I/F is always three-stated (inactiv?).

What do you exactly mean with "the module is set as a PCM master". According
to the datasheet "Ericsson Specific HCI Features for BASEBAND-B" (Rev. PA2,
dated 2000-01-14), there is only one command for setting the behavior of the
PCM I/F (Ericsson_Write_PCM_Settings). And as default, the Ericsoon module
should already be set as PCM master. We tried other settings, but didn't
observed any changes. Are there other settings I missed?

In general, there is little information about the voice interfaces. I
haven't found any information how one can select the proper I/F for SCO
connection: PCM or USB. The only reference I found was something about
ISOCHRONOUS ENDPOINTS EXPECTATIONS in the HCI USB Transport Layer (Bluetooth
core specs, page 770). Has anybody more information about this issue?


SCO link:
We have still an other problem: we are not able to build up a SCO
connection, since the Ericsson module reports 'maximum number of
connection'. I know the point to point connections limitation, but this
can't be true for a SCO connection, since an ACL connection has to be setup
before. What's wrong here?
Has anybody experiences with SCO links? Is this an Ericsson specific
problem? How does ist work with other Bluetooth chips (like CSR's BlueCore
01).


Any answers to these topics are really appreciated.

thanks in advance.

Bernard




________________________________________________________________________
Bernard Stauffer, dipl. El.-Ing. ETH, Computer Engineering & Communi-
cation Networks Lab, Swiss Federal Institute of Technology (ETH) Zuerich
Mail: ETHZ, TIK, ETZ-G75, Gloriastr. 35, CH-8092 Zuerich, Switzerland
Tel: +41-1-6327058 / Fax: +41-1-6321036 / mailto:stauffer@xxxxxxx.ch




-
To unsubscribe from this list: send the line "unsubscribe bluetooth-dev" in
the body of a message to majordomo@xxxxxxx.com