Cambridge-based fabless microcontroller firm Cyan has developed a 16-bit core delivering 0.71DMIPS/MHz at 50MHz from a 0.18µm process.
Specific power consumption is 0.65mW/MHz and deep sleep leakage is 4.5µA.
“We were able to start from a clean sheet of paper with all the knowledge of the latest CPU designs without any of the baggage,” designer Paul Hoayun told EW. “Our existing XAP2 core delivers roughly 0.3DMIPS/MHz, so the new CyCore is better than twice as good, and it has about the same number of gates.”
Not only is the core faster, but Cyan will not have to pay royalties to Cambridge Consultants, original designer of the XAP2.
CyCore has a Harvard load-store architecture with a prefetch-execute pipeline and mostly single-cycle execution. Cache cuts power consumption by reducing flash access.
“We wanted to get this out on a short time scale and keep it simple,” said Hoayun, “future versions may be pipelined to a greater depth.”
Future versions may also get more instructions.
“We hope this will be a family of devices and have been looking at instructions to add various functionalities: instructions to accelerate encryption and instructions for error correction are highly relevant to RF-type applications,” said Hoayun - Cyan has a tie-up with Micrel for RF reference designs and the firm’s original chips have found a market in low-power RF networks.
See: Cyan and Micrel to develop wireless metering systems
The instruction set has been designed to use less memory than XAP2. One consequence is that CyCore is not at all bit-level compatible with XAP2.
“We never considered making the core code compatible, it has a completely different register set,” said Cyan CTO Ken Wallace, “Migration for customers is not too difficult. Re-targeting C with our development tools is almost an invisible process.”
eCOG16E01 is the first silicon available with CyCore.
It is similar to the firm’s existing XAP-based eCOG1X, but through customer consultation the peripheral set has been cut down.
Now, there is one rather than two ADCs, no DACs, no USB interface and no Ethernet interface.
The PWMs are still there for motor switching - white goods controllers is another target application.
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