Техническая Спецификация для Atmel SAM4S-XPLD Atmel ATSAM4S-XPLD ATSAM4S-XPLD

 479

SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

At start-up, the Main On-Chip RC Oscillator frequency is 4 MHz.

Note:

MOSCRCF must be changed only if MOSCRCS is set in the PMC_SR register. Therefore MOSCRCF and 
MOSCRCEN cannot be changed at the same time.

Specifies the number of Slow Clock cycles multiplied by 8 for the Main Crystal Oscillator start-up time. 

0 = The Main On-Chip RC Oscillator is selected.

1 = The Main Crystal Oscillator is selected.

0 = The Clock Failure Detector is disabled.

1 = The Clock Failure Detector is enabled.

Note:

1. The slow RC oscillator must be enabled when the CFDEN is enabled. 

2. The clock failure detection must be enabled only when system clock MCK selects the fast RC Oscillator. 

3. Then the status register must be read 2 slow clock cycles after enabling. 

0x0

12_MHz

The Fast RC Oscillator Frequency is at 12 MHz (default)

0x1

8_MHz

The Fast RC Oscillator Frequency is at 8 MHz

0x2

4_MHz

The Fast RC Oscillator Frequency is at 4 MHz

0x37

PASSWD

Writing any other value in this field aborts the write operation.

Always reads as 0.