AMD-K6 Datasheet, PDF (212/346 Pages) Advanced Micro Devices – AMD-K6 Processor

AMD-K6^® Processor Data Sheet
Preliminary Information
20695H/0—March 1998
s Far jumps or calls cannot transfer control to a segment with
a base address requiring more than 20 bits, as in Real mode
segment-base addressing
s A20M# is masked
s Interrupt vectors use the Real-mode interrupt vector table
s The IF flag in EFLAGS is cleared (INTR not recognized)
s The TF flag in EFLAGS is cleared
s The NMI and INIT interrupts are disabled
s Debug register DR7 is cleared (debug traps disabled)
Figure 72 on page 195 shows the default map of the SMM
me mo ry a rea . It consis ts o f a 64 -Kbyte area, betwee n
0003_0000h and 0003_FFFFh, of which the top 32 Kbytes
(0003_8000h to 0003_FFFFh) must be populated with RAM.
The default code-segment (CS) base address for the area —
called the SMM base address —is at 0003_0000h. The top 512
bytes (0003_FE00h to 0003_FFFFh) contain a fill-down SMM
state-save area. The default entry point for the SMM service
routine is 0003_8000h.
194
System Management Mode (SMM)
Chapter 10