AMD LX 900@1.5W Computer Hardware User Manual


 
AMD Geode™ LX Processors Data Book 113
CPU Core Register Descriptions
33234H
5.5.2.5 SYSENTER/SYSEXIT Stack Pointer MSR (SYS_SP_MSR)
SYS_SP MSR is used by the SYSENTER instruction (fast system call) as the most privileged stack pointer.
5.5.2.6 SYSENTER/SYSEXIT Instruction Pointer MSR (SYS_IP_MSR)
SYS_IP MSR is used by the SYSENTER instruction (fast system call) as the offset into the most privileged code segment.
MSR Address 00000175h
Typ e R /W
Reset Value 00000000_00000000h
SYS_SP_MSR Register Map
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
RSVD
313029282726252423222120191817161514131211109876543210
ESP
SYS_SP_MSR Bit Descriptions
Bit Name Description
63:32 RSVD Reserved.
31:0 ESP Enter Stack Pointer. Stack pointer to be used after SYSENTER in most privileged code.
(Default = 0)
MSR Address 00000176h
Typ e R /W
Reset Value 00000000_00000000h
SYS_IP_MSR Register Map
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
RSVD
313029282726252423222120191817161514131211109876543210
EIP
SYS_IP_MSR Bit Descriptions
Bit Name Description
63:32 RSVD Reserved.
31:0 EIP Enter Instruction Pointer. Offset into the most privileged code segment. (Default = 0)