What devices support os-links?

What devices support os-links?

Post by Antero Met » Sat, 25 Dec 2004 04:00:38


I am looking for an alternative for C011 link chips. Do
ST20-series devices support transputer OS-links?

/Antero
 
 
 

What devices support os-links?

Post by Stephen Ma » Sat, 25 Dec 2004 07:27:37


I recall someone (more than one?) producing an FPGA design for an OS-link.
If you can't google it, try talking to Paul Walker at 4links as he had
interests in such things. Certainly 4links have synthesisable DS-links for
SpaceWire.

 
 
 

What devices support os-links?

Post by @lec wle » Sat, 25 Dec 2004 08:11:24


We have systhesized a lot of OS links in FPGA. I don't know myself, but
the guy who did it said it only took him a couple of days. We used a
StrongArm + FPGA as a transputer replacement.


--
@lec wley
 
 
 

What devices support os-links?

Post by rmeenak » Mon, 27 Dec 2004 01:12:57


THere are several FPGA-based alternatives. If you are into the set-top
boxes, then take a look at the following:

http://www.yqcomputer.com/

http://www.yqcomputer.com/

And the following generic implementation of the OS-Links:
http://www.yqcomputer.com/

Cheers,

Ram
 
 
 

What devices support os-links?

Post by Dave » Sun, 02 Jan 2005 03:10:15


set-top
http://www.yqcomputer.com/

The design at cate.com seems very specific to Altera. Anybody know of
a more generic C011/C012 (old style link, not T9000 data/strobe link)
implementation in VHDL or Verilog?

Thanks.

-Dave
 
 
 

What devices support os-links?

Post by rmeenak » Sun, 02 Jan 2005 11:47:45


of

Some set-top boxes (like Philips) have a ST20 that uses the old style
links. Here is yet another os-link design for the Philips set-top
boxes written in AHDL? which apparently can be "easily converted" to
VHDL. Might be useful to you...
http://www.yqcomputer.com/

Cheers,

Ram
 
 
 

What devices support os-links?

Post by Dave » Mon, 03 Jan 2005 10:28:06


link)

Thanks, Ram, that's exactly what I need.

-Dave
 
 
 

What devices support os-links?

Post by mike » Mon, 10 Jan 2005 03:19:42

Hi Dave!


I've taken a quick run over to this oslink-interface. os means
oversampling. Nothing there ... and you have to do it. Sampling far
away from the middle of a bit-cell is a flaw! Please check "Data to
Clock Phase Alignment XAPP225" from Xilinx.
( http://www.yqcomputer.com/ )

I have selected this approach for my pci-link-adapter and it works
still very well.

Your real challange is to handle different clockdomains and convert a
multiple continous byte stream protocol to a discontinous multibyte
block protocol with low systemimpact ;-)

Good Luck,

Mike
 
 
 

What devices support os-links?

Post by Dave » Tue, 11 Jan 2005 07:06:30


I thought, perhaps mistakenly, that the oversampling requirements for
the old-style links were not as stringent as, say, a standard serial
port because all the links are running at the same 10MHz rate to within
a few hundred parts per million. If 16X oversampling is OK for a UART,
how much is required for an old-style link? Abybody know how INMOS did
the implementation?


Don't the old-style links send discrete bytes? Maybe this is in
reference to the T9000 link?
Thank you for the information, Mike.

-Dave
 
 
 

What devices support os-links?

Post by @lec wle » Tue, 11 Jan 2005 08:04:09


You want to talk to Brian O'Neill about it, but I think he did it on 3x
oversampling. One of our engineers certainly did it on 4x oversampling.

--
@lec wley
 
 
 

What devices support os-links?

Post by August Wes » Tue, 11 Jan 2005 20:53:49

Jonathan Bromley < XXXX@XXXXX.COM > writes:


There was an inmos TRAM that reliably drove link signals over RS424
(or was if 485?). I can't tell you the number, as my data books are
400 miles away, but maybe Ram could look it up?

--
Can you search for what's not lost?
 
 
 

What devices support os-links?

Post by mike » Wed, 12 Jan 2005 00:51:53


Your problem is the phase between transmitter and receiver and not the
frequency. The same frequency is a prerequisit. I think, I've read
something with 4 times oversampling in the T9000 ds-os-link-converter
manuals.
My implementation uses 4 times .. with two clocks (20Mhz and
20Mhz/+90degrees) and both edges for the data-clock-alignment.


Yes, No ... ;-)

The question is: where will it be connected? Most interfaces/busses
are shared resources and there width is greater than 8 bit.

A "quick and dirty" estimate:

Interface: PCI 33MHz/32bit
One Link @20Mhz: 2.4 MB/s (bidirectional)

Burstmode 33MHz * 4B -> 133MB/s
-> 2.4/133 = 2% utilization

B004 IO-Poll 1 Status Rd + 1 Data Rd or Wr
1 PCI Access .. 6 Cycles
-> 12 Cycles per byte -> 33/12 -> 2,7MB/s
-> 2.4/2.7 = 90% utilization

So it's really importance to use burst mode 32bit transfers.
That's what I mean with "discontinous multibyte block protocol".

-Mike
 
 
 

What devices support os-links?

Post by mike » Wed, 12 Jan 2005 02:57:45

ADDENDUM:


Right manual, wrong value!

From: The T9000 Transputer Product Overview Manual (1. Edition 1991)
Page: 164 (IMS C100 system protocol converter, introduction)

.. T2/T4/T8-series transputer links consist of two wires, one in each
.. direction, and use a asynchronous bit-serial (byte-stream) protocol.
.. Each bit received is sampled five times and hence the links are
.. referred to as oversampled (OS) links. Each link provides a pair of
.. channels, one in each directions and can operate at up to
.. 20 MBits/sec, providing a bidirectional bandwidth of 2.4 MBytes/sec.

The right answer is 5 (if we assume that the linkimplementation from
C100 is in this point identical to the T2/T4/T8 transputers)

-Mike
 
 
 

What devices support os-links?

Post by rmeenak » Wed, 12 Jan 2005 03:52:56


Well, my databooks are about 20 miles away, but what you are refering
to is the differential link trams from INMOS. The part number is
IMSB415 and contained an RS422 (IIRC)....

Cheers,

Ram