Product Specs

Table Of Contents
19 CLOCK Clock control
Page
105
Register Offset Description
TASKS_LFCLKSTOP 0x00C Stop LFCLK source
EVENTS_HFCLKSTARTED 0x100 HFCLK oscillator started
INTENSET 0x304 Enable interrupt
LFCLKRUN 0x414 Status indicating that LFCLKSTART task has been triggered
CTIV 0x538 Calibration timer interval Retained
19.2.5 32.768 kHz synthesized from HFCLK (LFSYNT)
LFCLK can also be synthesized from the HFCLK clock source. The accuracy of LFCLK will then be the
accuracy of the HFCLK.
Using the LFSYNT clock avoids the requirement for a 32.768 kHz crystal, but increases average power
consumption as the HFCLK will need to be requested in the system.
19.3 Registers
Table 26: Instances
Base address
Peripheral
Instance
Description
Configuration
0x40000000
CLOCK
CLOCK
Clock control
Table 27: Register Overview
TASKS_HFCLKSTART 0x000 Start HFCLK crystal oscillator
TASKS_HFCLKSTOP 0x004 Stop HFCLK crystal oscillator
TASKS_LFCLKSTART 0x008 Start LFCLK source
TASKS_CAL 0x010 Start calibration of LFRC oscillator
TASKS_CTSTART 0x014 Start calibration timer
TASKS_CTSTOP 0x018 Stop calibration timer
EVENTS_LFCLKSTARTED 0x104 LFCLK started
EVENTS_DONE 0x10C Calibration of LFCLK RC oscillator complete event
EVENTS_CTTO 0x110 Calibration timer timeout
INTENCLR 0x308 Disable interrupt
HFCLKRUN 0x408 Status indicating that HFCLKSTART task has been triggered
HFCLKSTAT 0x40C HFCLK status
LFCLKSTAT 0x418 LFCLK status
LFCLKSRCCOPY 0x41C Copy of LFCLKSRC register, set when LFCLKSTART task was triggered
LFCLKSRC 0x518 Clock source for the LFCLK
TRACECONFIG 0x55C Clocking options for the Trace Port debug interface
19.3.1 INTENSET
Address offset: 0x304
Enable interrupt
Bit number
Id
Reset 0x00000000
31 30
0 0
29
0
28
0
27
0
26
0
25
0
24
0
23 22 21 20
0 0 0 0
19
0
18
0
17
0
16
0
15
0
14
0
13
0
12
0
11
0
10
0
9
0
8
0
7
0
6
0
5
0
4
D
0
3
C
0
2
0
1
B
0
0
A
0
Id RW Field
Value Id
Value
Description
A RW HFCLKSTARTED
Write '1' to Enable interrupt for HFCLKSTARTED event
See EVENTS_HFCLKSTARTED
Set
1
Enable
Disabled
0
Read: Disabled
Enabled
1
Read: Enabled
B RW LFCLKSTARTED
Write '1' to Enable interrupt for LFCLKSTARTED event
Set
1
See EVENTS_LFCLKSTARTED
Enable
Disabled
0
Read: Disabled
Enabled
1
Read: Enabled