SAM3S8C Atmel Corporation, SAM3S8C Datasheet - Page 471

• Manufacturer Part Number: SAM3S8C
• Manufacturer: Atmel Corporation

25.1.16.8
Name:
Address:
Access:
This register can only be written if the WPEN bit is cleared in
• MAINF: Main Clock Frequency
Gives the number of Main Clock cycles within 16 Slow Clock periods.
• MAINFRDY: Main Clock Ready
0 = MAINF value is not valid or the Main Oscillator is disabled or a measure has just been started by means of RCMEAS.
1 = The Main Oscillator has been enabled previously and MAINF value is available.
• RCMEAS: RC Oscillator Frequency Measure (write-only)
0 = No effect.
1 = restart a measure of the main RC frequency, MAINF will carry the new frequency as soon as a low to high transition
occurs on MAINFRDY flag.
The measure is performed on the main frequency (i.e. not limited to RC oscillator only) but if the main clock frequency
source is the fast crystal oscillator, the restart of the measure is unneeded because of the well known stability of crystal
oscillators.
471
471
31
23
15
–
–
7
SAM3S8/SD8
SAM3S8/SD8
PMC Clock Generator Main Clock Frequency Register
CKGR_MCFR
0x400E0424
30
22
14
Read-Write
–
–
6
29
21
13
–
–
5
RCMEAS
28
20
12
–
4
MAINF
MAINF
“PMC Write Protect Mode Register”
27
19
11
–
–
3
26
18
10
–
–
2
.
25
17
–
–
9
1
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
MAINFRDY
24
16
–
8
0