AMD Geodeā„¢ LX Processors Data Book 125
CPU Core Register Descriptions 33234H
5.5.2.16 XC Mode MSR (XC_MODE_MSR)
XC_MODE_MSR contains information about the current status of the processor.
MSR Address 00001211h
Type R/W
Reset Value 00000000_00000000h
XC_MODE_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
RSVD
DM_AC_STALL
FP_STALL
FP_ERROR
FP_BUSY
IP_BUSY
DM_BUSY
IF_BUSY
DM_EX_DELAY
IQ_EMPTY
WAIT_FPI NTR
FLUSHING
HALTED
SUSPENDED
NMI_ACTIVE
DMM_ACTIVE
SMM_ACTIVE
XC_MODE_MSR Bit Descriptions
Bit Name Description
63:16 RSVD (RO) Reserved (Read Only).
15 DM_AC_STALL
(RO)
Data Memory Subsystem Stall Address Calculation Unit (Read Only). DM wants no
more requests from AC.
14 FP_STALL (RO) Floating Point Stall (Read Only). FP is stalling the pipeline.
13 FP_ERROR
(RO)
Floating Point Error (Read Only). FP is reporting an error.
12 FP_BUSY (RO) Floating Point Busy (Read Only). FP is reporting that it is not idle.
11 IP_BUSY (RO) Instruction Pipeline Busy (Read Only). IP is reporting that it is not idle.
10 DM_BUSY (RO) Data Memory Subsystem Busy (Read Only). DM is reporting that it is not idle.
9 IF_BUSY (RO) Instruction Fetch Busy (Ready Only). IF is reporting that it is not idle.
8 DM_EX_DELAY
(RO)
Data Memory Subsystem Execution Delay (Read Only). Pipeline is waiting for DM to
provide instruction data.
7 IQ_EMPTY (RO) Instruction Queue Empty (Read Only). Instruction Queue is empty.
6 WAIT_FPINTR
(RO)
Wait for Floating Point Interrupt (Read Only). Processor is waiting for an external
maskable interrupt due to a FP error (CR0 NE bit is set, See Table 5-10 "CR0 Bit
Descriptions" on page 96). (Default = 0)
5 FLUSHING (RO) Flushing (Read Only). Processor is flushing the pipeline while waiting for DM to empty.
4HALTED (RO)Halted (Read Only). Processor is halted. (Default = 0)
3 SUSPENDED
(RO)
Suspended (Read Only). Processor is suspended. (Default = 0)
2NMI_ACTIVENon-Maskable Interrupt Active. Processor is in a NMI handler. (Default = 0)
1 DMM_ACTIVE Debug Management Mode. Processor is in debug management mode. (Default = 0)
0SMM_ACTIVESystem Management Mode. Processor is in system management mode. (Default = 0)