Hi All,

I am a new member to this group.
I have a query,

In C5501, McBSP as SPI for TDM bus is what I'm trying  to understand.

I want to know whether for C5501's McBSP as SPI can be used for TDM 
operation?

I have referred TMS320VC5501 McBSP Ref Guide (SPRU592E). The document 
says for SPI mode configuration 

XFRLEN1 & RFRLEN1 bits of XCR1 set to '0' meaning we must use a 
transmit/receive frame length of 1 serial 

word only. So in this case it does not become a TDM frame at all. 
Hence I myself conclude that C5501's McBSP as SPI can not be used for 
TDM operation.

Or is there any other method of using SPI mode for TDM operation?

Any clarifications or any type of help with documents is highly 
appreciated.

Thanks
Nagabhushan

Nagabhushan-

> I am a new member to this group.
> I have a query,
> 
> In C5501, McBSP as SPI for TDM bus is what I'm trying  to understand.
> 
> I want to know whether for C5501's McBSP as SPI can be used for TDM
> operation?
> 
> I have referred TMS320VC5501 McBSP Ref Guide (SPRU592E). The document
> says for SPI mode configuration
> 
> XFRLEN1 & RFRLEN1 bits of XCR1 set to '0' meaning we must use a
> transmit/receive frame length of 1 serial
> 
> word only. So in this case it does not become a TDM frame at all.
> Hence I myself conclude that C5501's McBSP as SPI can not be used for
> TDM operation.
> 
> Or is there any other method of using SPI mode for TDM operation?
> 
> Any clarifications or any type of help with documents is highly
> appreciated.

I'm assuming you need TDM comm between one 5501 and other devices -- otherwise why
not just use built-in McBSP support for TDM between multiple 55xx.

If this is correct, then my guess is that if you really want to use SPI format in a
multi-device TDM configuration, you will need to control the peripheral chip selects
(frame sync for TI chip) in a sequence that creates "time slots" so that only one
device transmits at one time.

But maybe something more than that can be done -- I'm not sure.  This is a good
question for TI Hotline / Knowledge Base.

-Jeff

Jeff,
   
  Thanks for inputs.
  I am very perticular to SPI mode with TDM bus operation.
   
  I also found that C54x supports TDM bus operation in SPI mode as they do not mention anywhere
in there Enhanced Peripherals doc (SPRU302) about the limitaion of frame length and hence the
no. of channels. But I am not sure why there's a limitaion for C5501?

  Thanks
  Nagabhushan

Jeff Brower <j...@signalogic.com> wrote:
          Nagabhushan-

> I am a new member to this group.
> I have a query,
> 
> In C5501, McBSP as SPI for TDM bus is what I'm trying to understand.
> 
> I want to know whether for C5501's McBSP as SPI can be used for TDM
> operation?
> 
> I have referred TMS320VC5501 McBSP Ref Guide (SPRU592E). The document
> says for SPI mode configuration
> 
> XFRLEN1 & RFRLEN1 bits of XCR1 set to '0' meaning we must use a
> transmit/receive frame length of 1 serial
> 
> word only. So in this case it does not become a TDM frame at all.
> Hence I myself conclude that C5501's McBSP as SPI can not be used for
> TDM operation.
> 
> Or is there any other method of using SPI mode for TDM operation?
> 
> Any clarifications or any type of help with documents is highly
> appreciated.

I'm assuming you need TDM comm between one 5501 and other devices -- otherwise why
not just use built-in McBSP support for TDM between multiple 55xx.

If this is correct, then my guess is that if you really want to use SPI format in a
multi-device TDM configuration, you will need to control the peripheral chip selects
(frame sync for TI chip) in a sequence that creates "time slots" so that only one
device transmits at one time.

But maybe something more than that can be done -- I'm not sure. This is a good
question for TI Hotline / Knowledge Base.

-Jeff

Nagabhushan H

>   Thanks for inputs.
>   I am very perticular to SPI mode with TDM bus operation.

Ok, but why?  What is the total list of devices that need to communicate -- this is
second time I've mentioned that.  You're asking people to help you but at the same
time they have to guess about what you're actually trying to accomplish?  Stealth
mode is not good use of the tech group.  Is this an academic exercise?  Or a real
project?

>   I also found that C54x supports TDM bus operation in SPI mode as they
>  do not mention anywhere in there Enhanced Peripherals doc (SPRU302)
>  about the limitaion of frame length and hence the no. of channels.

You're assuming that 54xx documentation is complete and accurate.  Did you actually
*try* a 54xx device with TDM and SPI?

> But I am not sure why there's a limitaion for C5501?

More accurate/complete documentation is my guess.

-Jeff

> Jeff Brower <j...@signalogic.com> wrote:
>           Nagabhushan-
> 
> > I am a new member to this group.
> > I have a query,
> >
> > In C5501, McBSP as SPI for TDM bus is what I'm trying to understand.
> >
> > I want to know whether for C5501's McBSP as SPI can be used for TDM
> > operation?
> >
> > I have referred TMS320VC5501 McBSP Ref Guide (SPRU592E). The document
> > says for SPI mode configuration
> >
> > XFRLEN1 & RFRLEN1 bits of XCR1 set to '0' meaning we must use a
> > transmit/receive frame length of 1 serial
> >
> > word only. So in this case it does not become a TDM frame at all.
> > Hence I myself conclude that C5501's McBSP as SPI can not be used for
> > TDM operation.
> >
> > Or is there any other method of using SPI mode for TDM operation?
> >
> > Any clarifications or any type of help with documents is highly
> > appreciated.
> 
> I'm assuming you need TDM comm between one 5501 and other devices -- otherwise why
> not just use built-in McBSP support for TDM between multiple 55xx.
> 
> If this is correct, then my guess is that if you really want to use SPI format in a
> multi-device TDM configuration, you will need to control the peripheral chip selects
> (frame sync for TI chip) in a sequence that creates "time slots" so that only
one
> device transmits at one time.
> 
> But maybe something more than that can be done -- I'm not sure. This is a good
> question for TI Hotline / Knowledge Base.
> 
> -Jeff