Register 1: SysTick Control and Status Register (STCTRL), offset 0x010
Note: This register can only be accessed from privileged mode.
The SysTick STCTRL register enables the SysTick features.
SysTick Control and Status Register (STCTRL)
Base 0xE000.E000
Offset 0x010
Type R/W, reset 0x0000.0004
16171819202122232425262728293031
COUNTreserved
ROROROROROROROROROROROROROROROROType
0000000000000000Reset
0123456789101112131415
ENABLEINTENCLK_SRCreserved
R/WR/WR/WROROROROROROROROROROROROROType
0010000000000000Reset
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.
0x000ROreserved31:17
Count Flag
DescriptionValue
The SysTick timer has not counted to 0 since the last time
this bit was read.
0
The SysTick timer has counted to 0 since the last time
this bit was read.
1
This bit is cleared by a read of the register or if the STCURRENT register
is written with any value.
If read by the debugger using the DAP, this bit is cleared only if the
MasterType bit in the AHB-AP Control Register is clear. Otherwise,
the COUNT bit is not changed by the debugger read. See the ARM®
Debug Interface V5 Architecture Specification for more information on
MasterType.
0ROCOUNT16
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.
0x000ROreserved15:3
Clock Source
DescriptionValue
External reference clock. (Not implemented for most Stellaris
microcontrollers.)
0
System clock1
Because an external reference clock is not implemented, this bit must
be set in order for SysTick to operate.
1R/WCLK_SRC2
July 24, 2012108
Texas Instruments-Production Data
Cortex-M3 Peripherals
OBSOLETE: TI has discontinued production of this device.