Datasheet

191
11011B–ATARM–21-Feb-12
SAM3N
10.22 System timer, SysTick
The processor has a 24-bit system timer, SysTick, that counts down from the reload value to
zero, reloads (wraps to) the value in the LOAD register on the next clock edge, then counts
down on subsequent clocks.
When the processor is halted for debugging the counter does not decrement.
The system timer registers are:
Table 10-33. System timer registers summary
Address Name Type
Required
privilege
Reset
value Description
0xE000E010 CTRL RW Privileged 0x00000004 “SysTick Control and Status Register” on page 192
0xE000E014 LOAD RW Privileged 0x00000000 “SysTick Reload Value Register” on page 193
0xE000E018 VAL RW Privileged 0x00000000 “SysTick Current Value Register” on page 194
0xE000E01C CALIB RO Privileged 0x0002904
(1)
“SysTick Calibration Value Register” on page 195
1. SysTick calibration value.