AMD is to include ARM Cortex-A5 CPUs inside its x86 APUs (Accelerated Processing Units) starting from next year. AMD's APUs currently consist of an x86-based processor and an integrated GPU, but the chip maker is to add an ARM CPU as well in order to support advanced security functions.
AMD will integrate ARM cores into a select few products at first and will eventually incorporate the chips into all of its APUs. The Cortex-A5 won't be used to run user-focused applications, but instead will take advantage of ARM's TrustZone security feature. TrustZone is already implemented in ARM SoCs, so AMD is buying into a widely-supported standard rather than developing a costly hardware security platform of its own. Intel's security platform, the Trusted Execution Technology, is not part of the x86 specification, so isn't covered by AMD's x86 license.
AMD announced in February that it was open to the ARM architecture, but it wasn't clear that it would be implementing changes so quickly. Two days ago it announced the formation of a computing open standards group in partnership with ARM and others. Although AMD hasn't publicly stated so, AnandTech believes that the integration of a Cortex-A5 chip "opens the door to comprehensive native ARM code execution in the future if AMD wanted to go that way."