Datasheet

256
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
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
* SCLK period.
RTPRES ≠ 0: The prescaler period is equal to RTPRES * SCLK period.
• 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).
• 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 RTC 1 Hz clock.
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