The memory interface of AMD K8 CPUs supports "Extended fixed-range MTRR Type-Field Encodings" which allows one to specify whether accesses to certain address ranges are executed by accessing RAM through the Direct Connect Architecture or by executing memory-mapped I/O.
The memory interface of AMD K8 CPUs supports "Extended fixed-range MTRR Type-Field Encodings" which allows one to specify whether accesses to certain address ranges are executed by accessing RAM through the Direct Connect Architecture or by executing memory-mapped I/O.