Datasheet

282
SAM4S Series [DATASHEET]
11100F–ATARM–29-Jan-14
15.5.1 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 period.
RTPRES ≠ 0: The prescaler period is equal to RTPRES * SLCK period.
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 1 Hz 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 RTC 1 Hz 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
76543210
RTPRES