The veteran processor architect got "a whole lot of new ideas working with both" ARM and x86 cores. But he gave only a few oblique hints on what AMD's ambidexterous chips might look like.
They will be closer in frequency to the 4 GHz of AMD's latest Kaveri x86 SoC than today's 2 GHz ARM chips, he said. For Skybridge, AMD tweaked its new Puma x86 cores to look more like an ARM V8 core.
AMD upgraded its current on-chip fabric, I/O and memory-management units so they could accommodate either the Puma+ or standard ARM cores in Skybridge. The fabric gets an upgrade for the custom ARM cores coming in 2016, probably made in a 16/14nm FinFET process.
"We got the IP, SoC and fabric right, then worked on how to plug the cores into them," he said. Skybridge provided an opportunity to "get the [SoC] plumbing right," he added.
Keller suggested AMD will consolidate its work on separate Bulldozer and Jaguar x86 cores into one processor line in the future. Meanwhile, the team had to bring up new verification and design flows for ARM SoCs.
Much of the architectural work on the upcoming AMD chips is done and the company is well along in implementing them, Keller suggested. AMD is apparently already well along in the custom designs that will use a 16/14nm FinFET process that he said "looks pretty good, we're happy with it."
"We are doing a new x86 and a new ARM core and a new [SoC] methodology -- that’s pretty daunting," Keller said.
"The fact Jim Keller came back [to AMD from Apple] telegraphed they would do something interesting -- he's the real deal," said Kevin Krewell, principal analyst of Tirias Research.
AMD estimates 80% of microprocessor revenues -- about $80 billion -- are for x86 or ARM chips.
Rory Read, AMD's chief executive promised the work will have significant impact on AMD's financials, still struggling out of the red zone.
"By the end of 2015, we'll have more than 50% of our revenues from new high growth segments" such as low power servers, semi-custom chips such as the videogame console SoCs and embedded systems, he said. By contrast, when Read joined AMD nearly three years ago "95% of our business was in PCs in a potentially declining market with an unhealthy duopoly," he added.
— Rick Merritt, Silicon Valley Bureau Chief, EE Times