Register 39: System Handler Control and State (SYSHNDCTRL), offset 0xD24
Note: This register can only be accessed from privileged mode.
The SYSHNDCTRL register enables the system handlers, and indicates the pending status of the
usage fault, bus fault, memory management fault, and SVC exceptions as well as the active status
of the system handlers.
If a system handler is disabled and the corresponding fault occurs, the processor treats the fault as
a hard fault.
This register can be modified to change the pending or active status of system exceptions. An OS
kernel can write to the active bits to perform a context switch that changes the current exception
type.
Caution – Software that changes the value of an active bit in this register without correct adjustment
to the stacked content can cause the processor to generate a fault exception. Ensure software that writes
to this register retains and subsequently restores the current active status.
If the value of a bit in this register must be modied after enabling the system handlers, a
read-modify-write procedure must be used to ensure that only the required bit is modied.
System Handler Control and State (SYSHNDCTRL)
Base 0xE000.E000
Offset 0xD24
Type R/W, reset 0x0000.0000
16171819202122232425262728293031
MEMBUSUSAGEreserved
R/WR/WR/WROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
MEMABUSA
reserved
USGAreservedSVCAMON
reserved
PNDSVTICKUSAGEPMEMPBUSPSVC
R/WR/WROR/WROROROR/WR/WROR/WR/WR/WR/WR/WR/WType
0000000000000000Reset
DescriptionResetTypeNameBit/Field
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x000ROreserved31:19
Usage Fault Enable
DescriptionValue
Disables the usage fault exception.0
Enables the usage fault exception.1
0R/WUSAGE18
Bus Fault Enable
DescriptionValue
Disables the bus fault exception.0
Enables the bus fault exception.1
0R/WBUS17
141July 24, 2012
Texas Instruments-Production Data
Stellaris
®
LM3S6G65 Microcontroller
OBSOLETE: TI has discontinued production of this device.
