6-28
System Design
AMD-K5 Processor Technical Reference Manual
18524C/0—Nov1996
6.3.3
SMM Revision Identifier
The SMM revision identifier at offset FEFCh in the SMM state-
save area specifies the version of SMM and the extensions that
are available on the processor. The SMM revision identifier
fields are as follows:
■
Bits 31–18—reserved
■
Bit 17—SMM base address relocation (always 1 = enabled)
■
Bit 16—I/O trap restart (always 1 = enabled)
■
Bits 15–0—SMM revision level = 0000
These fields are the same as in the Pentium processor. Unlike
the Pentium processor, however, the I/O trap restart and the
SMM base address relocation functions are always enabled in
the AMD-K5 processor and do not need to be specifically
enabled.
6.3.4
SMM Base Address
During RESET, the processor sets the code-segment (CS) base
address for the SMM memory area—the SMM Base Address—to
its default, 0003_0000h. The SMM base address at offset FEF8
in the SMM state-save area can be changed by the SMM ser-
vice routine to any address that is aligned to a 32-Kbyte bound-
ary. (Locations not aligned to a 32-Kbyte boundary cause the
processor to enter the Shutdown state when executing the
RSM instruction.)
FF04
I/O Restart EDI
32
read-only
FF02
Halt Restart Slot
16
(See Section 6.3.5)
read/write
FF00
I/O Trap Restart Slot
16
(See Section 6.3.7)
read/write
FEFC
SMM Revision Identifier
32
(See Section 6.3.3)
read-only
FEF8
SMM Base Address
32
(See Section 6.3.4)
read/write
FE00–FEF4
reserved
32
—
Table 6-2. SMM State-Save Area Map (continued)
Offset (hex)
Contents
Size (bits)
Type
Notes:
1. Locations marked “reserved” may change in future processors.
2. Writing locations marked as “read-only” has unpredictable results.
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...