The latest AMD programmer manuals, dated June 2015, include the
RDRAND instruction in the instruction set. For completeness, it lacks
RDSEED. Confer, AMD64 Architecture Programmer’s Manual Volume 3: General-Purpose and System Instructions, page 278.
The description includes the text:
Loads the destination register with a hardware-generated random value.
I'm having trouble finding information on AMD's circuit and other design/implementation details. I'm not getting specific hits when searching AMD's site, and a general web search is returning a lot of noise dominated by Intel (not Intel's fault, its just the way it is).
What is known about AMD's circuit?
Based on @Richie comments (it was a good lead): according to NIST's Validated FIPS 140-1 and FIPS 140-2 Cryptographic Modules, AMD does not have an approved module. Additionally, according to NIST's Modules In Process, AMD does not have something in evaluation.