transputer link hardware

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2 total messages Started by JAAP Thu, 23 Nov 1989 16:22

#415

Author: JAAP
Date: Thu, 23 Nov 1989 16:22

27 lines
1325 bytes

Hello mailing list,
 
As we all know, the data entering a transputer (or another
transputer link compatible device) via a link, is not
synchronized with the internal clock of that device. The
device has to synchronize the incoming data with its
internal clock before these data can be processed.
 
For the design of an IC with transputer link compatible
inputs, we would like to know how this problem is solved in
the hardware of a transputer, or how people think that this
problem is solved or could be solved. We think that we have
found a good solution, which can be implemented easily.
However some other opinions about this topic would be
welcome. Of course we would be glad to discuss our solution
with interested people.
 
Thanks in advance, Jaap.
 
Jaap Hofstede
Dept. Computer Science (INF/SPA)
University of Twente
PB 217
7500 AE ENSCHEDE
Netherlands
Tel: +31 53 893788
Email: JAAP@HENUT5.NL

transputer link hardware

#419

Author: Derek Coppen
Date: Fri, 24 Nov 1989 10:45

17 lines
1377 bytes

Transputers use a PLL to generate a high frequency clock
(100MHz I believe) to time in the serial data just the same as
a conventional UART.

In my application I wanted to connect a link adaptor to an
Ethernet controller. The INMOS link adaptors at 20Mbaud
don't go fast enough to support a 10Mbaud ethernet link partly
because of the frame overhead and servicing latency, but mainly
because the adaptors don't support the overlapped acknowledge
protocol. My solution was to implement a double buffered
overlapped ack link adaptor on a Xilinx LCA chip using both edges
of a 40MHZ crystal clock instead of the 100MHz PLL source.
There was enough room left on the chip (the smallest in the
range) to implement a finite state machine to control a 9 bit
bidirectional data bus with read and write strobes to the Seeq8003
ether controller. As a bonus a 20MHz output feeds the manchester
encoder saving an extra crystal.

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