PCHCTRLmn

Bit31	30	29	28	27	26	25	24

Access
Reset
Bit23	22	21	20	19	18	17	16

Access
Reset
Bit15	14	13	12	11	10	9	8

Access
Reset
Bit7	6	5	4	3	2	1	0
WRTLOCK	CHEN			GEN[3:0]
AccessR/W	R/W			R/W	R/W	R/W	R/W
Reset0	0			0	0	0	0

Write Lock

After this bit is set to '1', further writes to the PCHCTRLm register will be discarded. The control register of the corresponding Generator n (GENCTRLn), as assigned in PCHCTRLm.GEN, will also be locked. It can only be unlocked by a Power Reset.

Note that Generator 0 cannot be locked.

Value	Description
0	The Peripheral Channel register and the associated Generator register are not locked
1	The Peripheral Channel register and the associated Generator register are locked

Channel Enable

This bit is used to enable and disable a Peripheral Channel.

Value	Description
0	The Peripheral Channel is disabled
1	The Peripheral Channel is enabled

Generator Selection

This bit field selects the Generator to be used as the source of a peripheral clock, as shown in the table below:

Table 1. Generator Selection
Value	Description
0x0	Generic Clock Generator 0
0x1	Generic Clock Generator 1
0x2	Generic Clock Generator 2
0x3	Generic Clock Generator 3
0x4	Generic Clock Generator 4
0x5	Generic Clock Generator 5
0x6	Generic Clock Generator 6
0x7	Generic Clock Generator 7
0x8	Generic Clock Generator 8
0x9 - 0xF	Reserved

Table 2. Reset Value after a User Reset or a Power Reset
Reset	PCHCTRLm.GEN	PCHCTRLm.CHEN	PCHCTRLm.WRTLOCK
Power Reset	0x0	0x0	0x0
User Reset	If WRTLOCK = 0 : 0x0 If WRTLOCK = 1: no change	If WRTLOCK = 0 : 0x0 If WRTLOCK = 1: no change	No change

A Power Reset will reset all the PCHCTRLm registers.

A User Reset will reset a PCHCTRL if WRTLOCK=0, or else, the content of that PCHCTRL remains unchanged.

PCHCTRL register Reset values are shown in the table PCHCTRLm Mapping.

Table 3. PCHCTRLm Mapping
index(m)	Name	Description
0	GCLK_DPLL	FDPLL96M input clock source for reference
1	GCLK_DPLL_32K	FDPLL96M 32kHz clock for FDPLL96M internal clock timer
2	GCLK_EIC	EIC
3	GCLK_FREQM_MSR	FREQM Measure
4	GCLK_FREQM_REF	FREQM Reference
5	-	Reserved
6	GCLK_EVSYS_CHANNEL_0	EVSYS_CHANNEL_0
7	GCLK_EVSYS_CHANNEL_1	EVSYS_CHANNEL_1
8	GCLK_EVSYS_CHANNEL_2	EVSYS_CHANNEL_2
9	GCLK_EVSYS_CHANNEL_3	EVSYS_CHANNEL_3
10	GCLK_EVSYS_CHANNEL_4	EVSYS_CHANNEL_4
11	GCLK_EVSYS_CHANNEL_5	EVSYS_CHANNEL_5
12 - 17	-	Reserved
18	GCLK_SERCOM[0,1,2,3]_SLOW	SERCOM[0,1,2,3]_SLOW
19	GCLK_SERCOM0_CORE	SERCOM0_CORE
20	GCLK_SERCOM1_CORE	SERCOM1_CORE
21	GCLK_SERCOM2_CORE	SERCOM2_CORE
22	GCLK_SERCOM3_CORE	SERCOM3_CORE
23	-	Reserved
24	-	Reserved
25	-	Reserved
26	-	Reserved
27	-	Reserved
28	GCLK_TCC0, GCLK_TCC1	TCC0,TCC1
29	GCLK_TCC2	TCC2
30	GCLK_TC0, GCLK_TC1	TC0,TC1
31	GCLK_TC2, GCLK_TC3	TC2,TC3
32	GCLK_TC4	TC4
33	GCLK_ADC0	ADC0
34	-	Reserved
35	-	Reserved
36	-	Reserved
37	GCLK_PTC	PTC
38	GCLK_CCL	CCL
39	-	Reserved
40	GCLK_AC	AC

Bit 7 – WRTLOCK: Write Lock

Bit 6 – CHEN: Channel Enable

Bits 3:0 – GEN[3:0]: Generator Selection