System Management Mode (SMM)
6-25
18524C/0—Nov1996
AMD-K5 Processor Technical Reference Manual
6.3.2
SMM State-Save Area
When the processor acknowledges an SMI interrupt by assert-
ing SMIACT, it saves its state in the 512-byte SMM state-save
area shown in Table 6-2. The save begins at the top of the SMM
memory area (SMM Base A FFFFh) and fills down to
SMM base a FE00h.
Table 6-2 shows the offsets in the SMM state-save area relative
to the SMM base address. The SMM service routine can alter
any of the read/write values in the state-save area. The con-
tents of any reserved locations in the state-save area are not
necessarily the same between the AMD-K5 processor and the
Pentium or 486 processors.
Table 6-1. Initial State of Registers in SMM
Register
Initial Contents
Selector
Base
Attributes
Limit
CS
3000h
0003_0000h
(see Section 6.3.4)
16-bit, expand-up
4 Gbytes
DS
0000h
0000_0000h
16-bit, expand-up
4 Gbytes
ES
0000h
0000_0000h
16-bit, expand-up
4 Gbytes
FS
0000h
0000_0000h
16-bit, expand-up
4 Gbytes
GS
0000h
0000_0000h
16-bit, expand-up
4 Gbytes
SS
0000h
0000_0000h
16-bit, expand-up
4 Gbytes
General-Purpose
Unmodified
EFLAGS
0000_0002h
EIP
0000_8000h
CR0
Bits 0, 2, 3, 31 cleared (PE, EM, TS, PG). Others are unmodified.
CR4
0000_0000h
GDTR
Unmodified
LDTR
Unmodified
IDTR
Unmodified
TR
Unmodified
DR7
Unmodified
DR6
Undefined
Summary of Contents for AMD-K5
Page 1: ...AMD K5 Processor Technical Reference Manual TM...
Page 10: ...x AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 24: ...1 4 Overview AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 54: ...2 30 Internal Architecture AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 116: ...4 26 Performance AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 356: ...6 44 System Design AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 380: ...7 24 Test and Debug AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 396: ...A 16 AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...
Page 406: ...I 10 Index AMD K5 Processor Technical Reference Manual 18524C 0 Nov1996...