Atmel SAM4L Xplained Pro Evaluation Kit Atmel ATSAM4L-XPRO ATSAM4L-XPRO Data Sheet
Product codes
ATSAM4L-XPRO
166
42023E–SAM–07/2013
ATSAM4L8/L4/L2
12.6.3.3
Continuous Mode
When BOD18/33CTRL.MODE is zero, the BOD18/33 operates in continuous mode. In continu-
ous mode the BOD18/33 is enabled and continously monitoring the supply voltage. The
continuos mode is the default mode.
ous mode the BOD18/33 is enabled and continously monitoring the supply voltage. The
continuos mode is the default mode.
12.6.3.4
Sampling Mode
The sampling mode, also called the one-shot mode, is a low power mode where the BOD18/33
is being repeatedly enabled by incoming positive edges from a configurable choice of sampling
clock sources including the System RC oscillator, the 32 KHz crystal oscillator (OSC32K) and
the RC 32KHz oscillator (RC32K). In sampling mode, the BOD18/33 will monitor the
VDDIO/VDDCORE voltages for a very short amount of time before it turns itself off again. Sam-
pling mode is enabled by writing a one to BOD18/33CTRL.MODE. The frequency of the
B O D 1 8 / 3 3 o n e - s h o t p u l s e s c a n b e v a r i e d b y t h e P r e s c a l e r S e l e c t f i e l d i n t h e
BOD18/33SAMPLING register (BOD18/33SAMPLING.PSEL).
is being repeatedly enabled by incoming positive edges from a configurable choice of sampling
clock sources including the System RC oscillator, the 32 KHz crystal oscillator (OSC32K) and
the RC 32KHz oscillator (RC32K). In sampling mode, the BOD18/33 will monitor the
VDDIO/VDDCORE voltages for a very short amount of time before it turns itself off again. Sam-
pling mode is enabled by writing a one to BOD18/33CTRL.MODE. The frequency of the
B O D 1 8 / 3 3 o n e - s h o t p u l s e s c a n b e v a r i e d b y t h e P r e s c a l e r S e l e c t f i e l d i n t h e
BOD18/33SAMPLING register (BOD18/33SAMPLING.PSEL).
f
sampling
= f
clk_presc
/
2
(PSEL+1)
Since the sampling mode clock is different from the PB clock domain, synchronization among
the clocks is necessary.
the clocks is necessary.
shows a block diagram of the sampling mode. The
BOD18/33 synchronization ready bit in PCLKSR (PCLKSR.BOD18/33SYNRDY) shows the
ready status of the synchronizer. Writing attempts to the BOD18/33SAMPLING register are
ignored while PCLKSR.BOD18/33SYNRDY is zero.
ready status of the synchronizer. Writing attempts to the BOD18/33SAMPLING register are
ignored while PCLKSR.BOD18/33SYNRDY is zero.
Figure 12-3. Sampling Mode Block Diagram
12.6.3.5
Clock Sources
The clock mux is used to select the clock source for the sampling mode. The clock source is
E n a b l e d / D i s a b l e d b y t h e C l o c k E n a b l e b i t i n t h e B O D 1 8 / 3 3 S A M P L I N G r e g i s t e r
(BOD18/33SAMPLING.CEN). The Clock Source Select bit (BOD18/33SAMPLING.CSSEL) is
used to select the clock source for the sampling mode.
E n a b l e d / D i s a b l e d b y t h e C l o c k E n a b l e b i t i n t h e B O D 1 8 / 3 3 S A M P L I N G r e g i s t e r
(BOD18/33SAMPLING.CEN). The Clock Source Select bit (BOD18/33SAMPLING.CSSEL) is
used to select the clock source for the sampling mode.
There are two possible clock sources for the sampling prescaler:
PRESCALER
SYNCHRONIZER
PB
INTERFACE
Unsync
Bus
fsampling
OSC32K or RC32K
RCSYS
CSSEL
sync
Bus
CLK_PB
Clk_presc
CEN
PSEL
MODE