Sunday, November 28, 2010

It's About Time

We care about time. An ongoing effort is to improve the quality of timestamp available to IP cores inside an FPGA to sub-nanosecond precision. One way forward is to use a stable, but not terribly accurate, on-board XO; and then to discipline it to a highly-accurate, but transient, reference from a GPS. Our approach uses a PI servo that is smart about when to freewheel. No magic. Just math.

Agilent 53230A 20pS Counter/Timer

Saturday, November 13, 2010

Narcissism of Small Differences

One of Seth's posts, as it often does, got me thinking.
  • emacs vs vi
  • VHDL vs Verilog
  • AXI vs OCP
The good news is that we care. I was going to add "Functional vs Imperative", then reflected, not such a small difference.

NetFPGA-10G and OpenCPI

Xilinx ran an article in their "Xcell Journal" describing NetFPGA-10G and the supporting role of OpenCPI.

At Xilinx Research Labs (Dublin)

Friday, October 22, 2010

10Gb Ethernet

We've been fortunate to have the opportunity to contribute to the NetFPGA-10Gb effort some of our expertise in PCIe DMA. Just back from a few days in Dublin sorting out the twisty bits. A great team!

PCIe DMA (October-2010)

Tuesday, August 24, 2010

Abstract and Concrete

There's no doubt that Hardware/Software co-design is a popular and challenging topic. In the embedded world, there is an added twist that real world voltage potentials exist and currents flow, as a result of the hardware and software. It's a system! Throughput, Latency, and Power that you can actually measure unambiguously!
We find it grounding to put drafty concepts on simple footings.

AR RF Bench (August-2010)

Friday, June 18, 2010


OCP and AXI seem a lot like Coke and Pepsi. RTL interface specifications and refreshing cola beverages. The choice of one or another does not matter at a certain level of abstraction. As an application-domain specifier, you may not care very much: "I'd like a stream interface please". Of course, the particular dining establishment you are visiting may respond to you "Oh, we don't have Coke, is Pepsi OK?"
This seems to have worked out well, at least with the cola beverage thing. And we are hoping the same will play out with OCP and AXI. Some establishments will have a predilection for one or the other. That's fine. Both OCP and AXI can provide interface patterns suitable for control, streaming, and messaging. We've abstracted these patterns in OpenCPI's Worker Interface Profiles. These interface patterns for RTL are like classic, diet and caffeine-free for cola.

Sometimes work allows some laughs (FCCM-2010)

Wednesday, May 12, 2010

The Correct Abstraction

The science and math behind the business of engineering is terrific. There is often a spectrum of choice for a particular implementation. That hardware and software can be abstracted in a similar fashion is hugely empowering. More choice! But we need metrics, hard quantitative measures to validate our decisions. Otherwise it's just qualitative balance.

4DSP FMC Card (2010)

ADO Firmware (1981)

Monday, April 26, 2010

Preparing for FCCM Charlotte

FCCM-2010 is in Charlotte in a week. There is a lot to prepare.

Napa has wine, what will Charlotte offer?

Saturday, March 6, 2010

Well Connected

Validating performance of ADCs and DACs is hard enough for the converter and board vendors. We have those challenges, as well as system level concerns. When you place an converter a few cm from a 100W GPU, how would you think the SFDR would change? Fun stuff.

GPU and FPGA Love

Sunday, January 24, 2010

Big DAC Attack

We've been putting some miles on the amazing RF ADCs and DACs that are now available. In particular, we like the Maxim MAX19693, a 4GSPS 12b DAC that is exceptionally well-targeted at our market's needs.

RF Bow-Tie