
281
SAM4CP [DATASHEET]
43051E–ATPL–08/14
16.5.1 Real-time Timer Mode Register
Name:
RTT_MR
Address:
0x400E1430
Access:
Read/Write
RTPRES: Real-time Timer Prescaler Value
Defines the number of SLCK periods required to increment the Real-time timer. RTPRES is defined as follows:
RTPRES = 0: The prescaler period is equal to 2
16
* SLCK periods.
RTPRES = 1 or 2: forbidden.
RTPRES
≠
0, 1 or 2: The prescaler period is equal to RTPRES * SLCK periods.
Note:
The RTTINCIEN bit must be cleared prior to writing a new RTPRES value.
ALMIEN: Alarm Interrupt Enable
0 = The bit ALMS in RTT_SR has no effect on interrupt.
1 = The bit ALMS in RTT_SR asserts interrupt.
RTTINCIEN: Real-time Timer Increment Interrupt Enable
0 = The bit RTTINC in RTT_SR has no effect on interrupt.
1 = The bit RTTINC in RTT_SR asserts interrupt.
RTTRST: Real-time Timer Restart
0 = No effect.
1 = Reloads and restarts the clock divider with the new programmed value. This also resets the 32-bit counter.
RTTDIS: Real-time Timer Disable
0 = The real-time timer is enabled.
1 = The real-time timer is disabled (no dynamic power consumption).
Note:
RTTDIS is write only.
RTC1HZ: Real-Time Clock 1Hz Clock Selection
0 = The RTT 32-bit counter is driven by the 16-bit prescaler roll-over events.
1 = The RTT 32-bit counter is driven by the 1 Hz RTC clock.
Note:
RTC1HZ is write only.
31
–
30
–
29
–
28
–
27
–
26
–
25
–
24
RTC1HZ
23
–
22
–
21
–
20
19
–
18
17
16
RTTDIS
RTTRST
RTTINCIEN
ALMIEN
15
14
13
12
11
10
9
8
RTPRES
7
6
5
4
3
2
1
0
RTPRES