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From: John_H on 10 Mar 2010 22:08
On Mar 10, 7:06 pm, Jon Elson <jmel...(a)wustl.edu> wrote:
>
> But, if you replace N counters with one adder/subtracter and a BRAM, it
> may well save real estate.  Muxing 2 counters seems pointless, but maybe
> when it gets to replacing 8 counters with one add/sub block it pays off.
> Even at 8 units it may just be a lot simpler to leave it dedicated
> hardware.  If I had the I/O lines, I could probably multiplex 40
> counters at 1 MHz to one add/sub running at 40 MHz and save a BUNCH of
> area, but with the index pulse, each counter would take 3 inputs for 120
> pins.  We don't need 40 quadrature counters on one chip, anyway.
>
> Jon

The thing I liked about multiplexing large counters (I had about 7
values I needed to keep track of) was the reduction in readout logic.
If I use a distributed CLB SelectRAM for the count values, I can read
multiple values from the memory without adding (much) readout logic.

In my case, I had 27-bit counters which were only read after the
counting events so the CLB SelectRAM was single port. Seven 27-bit
counters and associated readout, implemented in around 60 LUTs. Not
bad. The "simple" approach would have been about 300 LUTs once
readout is thrown in.
From: -jg on 18 Mar 2010 03:43
On Mar 3, 12:22 am, Symon <symon_bre...(a)hotmail.com> wrote:
> This lot seems to be revealing a bit more about their stuff.
>
and still more info
http://www.eeproductcenter.com/pld-fpga/brief/showArticle.jhtml;jsessionid=BPWGVULEVILDOQSNDLSCKHA?articleID=223800194

[" the chips will sample in third quarter and go into mass production
in Q4 2010. "]

["A1EC02, A1EC03, A1EC04, and the A1EC06 with between 220,000 and
630,000 look-up tables per device. All four parts have 5.5-Mbytes of
RAM, 920 parallel I/Os and 44 PLLs, Tabula said The A1EC06 has 1,280
multiplier-accumulator blocks. Designed for a range of applications,
ABAX devices will initially target the telecom, enterprise, and
wireless infrastructure markets and all the initial devices in the
family include 48 serial transceivers operating at between 55-Mbit/s
and 6.5-Gbit/s. "]

A1EC04 is $150 per unit for orders of 2,000 units

That's a lot of engineering...

-jg
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