iv
Contents
AMD-K6
Processor BIOS Design
21329L/0—December 1999
System Management Mode (SMM) . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
State-Save Map Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
I/O Trap Dword Differences . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Model-Specific Registers (MSRs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Standard MSRs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Machine-Check Address Register (MCAR) and
Machine-Check Type Register (MCTR). . . . . . . . . . . . . . . . . . 15
Test Register 12 (TR12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Time Stamp Counter (TSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
AMD-K6
Processor Models 6, 7 and AMD-K6-2
Processor Model 8/[7:0] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Extended Feature Enable Register (EFER). . . . . . . . . . . . . . 16
Write Handling Control Register (WHCR). . . . . . . . . . . . . . . 17
SYSCALL/SYSRET Target Address Register (STAR) . . . . . . 19
AMD-K6
-2 Processor Model 8/[F:8] . . . . . . . . . . . . . . . . . . . . 20
Extended Feature Enable Register (EFER). . . . . . . . . . . . . . 20
Write Handling Control Register (WHCR). . . . . . . . . . . . . . . 23
SYSCALL/SYSRET Target Address Register (STAR) . . . . . . 26
UC/WC Cacheability Control Register (UWCCR) . . . . . . . . . 26
Processor State Observability Register (PSOR). . . . . . . . . . .30
Page Flush/Invalidate Register (PFIR) . . . . . . . . . . . . . . . . . . 31
AMD-K6
-III
Processor Model 9. . . . . . . . . . . . . . . . . . . . . . . . 33
Extended Feature Enable Register (EFER). . . . . . . . . . . . . . 33
Write Handling Control Register (WHCR). . . . . . . . . . . . . . . 34
SYSCALL/SYSRET Target Address Register (STAR) . . . . . . 35
UC/WC Cacheability Control Register
(UWCCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Processor State Observability Register (PSOR). . . . . . . . . . .35
Page Flush/Invalidate Register (PFIR) . . . . . . . . . . . . . . . . . . 36
Level-2 Cache Array Access Register (L2AAR) . . . . . . . . . . .36
New AMD-K6
Processor Instructions . . . . . . . . . . . . . . . . . . . . . . . . 41
Additional Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Software Timing Dependencies Relative to
Memory Controller Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Pipelining Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Read-Only Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42