Short for Audio Modem Riser, an Intel specification that defines a new architecture for the design of motherboards.
AMR lets manufacturers create motherboards without analog I/O functions. Instead, these functions are placed on a separate card--with the codec chip--which plugs in perpendicular to the motherboard so that the motherboard and "riser" card form a right angle.
Separating the analog I/O functions from the motherboard means higher audio quality and reduced production delays. Prior to the AMR specification, motherboard analog I/O functions went through a lengthy FCC and international telecom certification process.