at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 301

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

26.9.7
Register Name:CKGR_MOR
Access Type:Read-write
• MOSCEN: Main Oscillator Enable
A crystal must be connected between XIN and XOUT.
0 = The Main Oscillator is disabled.
1 = The Main Oscillator is enabled. OSCBYPASS must be set to 0.
When MOSCEN is set, the MOSCS flag is set once the Main Oscillator startup time is achieved.
• OSCBYPASS: Oscillator Bypass
0 = No effect.
1 = The Main Oscillator is bypassed. MOSCEN must be set to 0. An external clock must be connected on XIN.
When OSCBYPASS is set, the MOSCS flag in PMC_SR is automatically set.
Clearing MOSCEN and OSCBYPASS bits allows resetting the MOSCS flag.
• OSCOUNT: Main Oscillator Start-up Time
Specifies the number of Slow Clock cycles multiplied by 8 for the Main Oscillator start-up time.
6384B–ATARM–15-Dec-08
31
23
15
–
–
7
–
PMC Clock Generator Main Oscillator Register
30
22
14
–
–
6
–
29
21
13
–
–
5
–
28
20
12
–
–
4
–
OSCOUNT
27
19
11
–
–
3
–
AT91SAM9G20 Preliminary
26
18
10
–
–
2
–
OSCBYPASS
25
17
–
–
9
1
MOSCEN
24
16
–
–
8
0
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