Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet
Product codes
AT91SAM9N12-EK
193
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
22.12.7 PMC Clock Generator Main Oscillator Register
Name:
CKGR_MOR
Address:
0xFFFFFC20
Access:
Read-write
• KEY: Password
Should be written at value 0x37. Writing any other value in this field aborts the write operation.
• MOSCXTEN: Main Crystal Oscillator Enable
A crystal must be connected between XIN and XOUT.
0: The Main Crystal Oscillator is disabled.
1: The Main Crystal Oscillator is enabled. MOSCXTBY must be set to 0.
When MOSCXTEN is set, the MOSCXTS flag is set once the Main Crystal Oscillator startup time is achieved.
• MOSCXTBY: Main Crystal Oscillator Bypass
0: No effect.
1: The Main Crystal Oscillator is bypassed. MOSCXTEN must be set to 0. An external clock must be connected on XIN.
When MOSCXTBY is set, the MOSCXTS flag in PMC_SR is automatically set.
Clearing MOSCXTEN and MOSCXTBY bits allows resetting the MOSCXTS flag.
• MOSCRCEN: Main On-Chip RC Oscillator Enable
0: The Main On-Chip RC Oscillator is disabled.
1: The Main On-Chip RC Oscillator is enabled.
When MOSCRCEN is set, the MOSCRCS flag is set once the Main On-Chip RC Oscillator startup time is achieved.
• MOSCXTST: Main Crystal Oscillator Start-up Time
Specifies the number of Slow Clock cycles multiplied by 8 for the Main Crystal Oscillator start-up time.
• MOSCSEL: Main Oscillator Selection
0: The Main On-Chip RC Oscillator is selected.
1: The Main Crystal Oscillator is selected.
• CFDEN: Clock Failure Detector Enable
0: The Clock Failure Detector is disabled.
1: The Clock Failure Detector is enabled.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
CFDEN
MOSCSEL
23
22
21
20
19
18
17
16
KEY
15
14
13
12
11
10
9
8
MOSCXTST
7
6
5
4
3
2
1
0
–
–
–
–
MOSCRCEN
–
MOSCXTBY
MOSCXTEN