8 pmc clock generator main oscillator register – Rainbow Electronics AT91CAP9S250A User Manual
Page 372
372
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
29.9.8
PMC Clock Generator Main Oscillator Register
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.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
OSCOUNT
7
6
5
4
3
2
1
0
–
–
–
–
–
–
OSCBYPASS
MOSCEN