3-1
18524C/0—Nov1996 AMD-K5 Processor Technical Reference Manual
3
Software Environment and
Extensions
The AMD-K5 processor is compatible with the instruction set,
programming model, memory management mechanisms, and
other software infrastructure supported by the 486 and Pen-
tium (735\90, 815\100) processors. Operating system and appli-
cation software that runs on the Pentium processor can be
executed on the AMD-K5 processor without modification.
Because the AMD-K5 processor takes a significantly different
approach to implementing the x86 architecture, some subtle
differences from the Pentium processor may be visible to sys-
tem and code developers. These differences are described in
Appendix A.
The AMD-K5 processor implements the following extensions to
the 486 architecture:
■ 4-Mbyte Page Size
■ Global Pages
■ Protected Virtual Extensions
■ Virtual-8086 Mode Extensions (VME)
■ Machine-Check Registers and Exceptions
■ Model-Specific Registers (MSRs)
■ Time Stamp Counter (TSC)
■ New Instructions: CPUID, CMPXCHG8B, MOV to and from
CR4, RDTSC, RDMSR, WRMSR, and RSM
■ I/O Breakpoints
To Next Page
Loading...
