Atmel ARM-Based Evaluation Kit for SAM4S16C, 32-Bit ARM® Cortex® Microcontroller ATSAM4S-WPIR-RD ATSAM4S-WPIR-RD Data Sheet
Product codes
ATSAM4S-WPIR-RD
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
286
15.
Real-time Timer (RTT)
15.1
Description
The Real-time Timer (RTT) is built around a 32-bit counter used to count roll-over events of the programmable 16-
bit prescaler driven from the 32 kHz slow clock source. It generates a periodic interrupt and/or triggers an alarm on
a programmed value.
The RTT can also be configured to be driven by the RTC 1 Hz signal, thus taking advantage of a calibrated 1 Hz
The RTT can also be configured to be driven by the RTC 1 Hz signal, thus taking advantage of a calibrated 1 Hz
clock.
The slow clock source can be fully disabled to reduce power consumption when only an elapsed seconds count is
The slow clock source can be fully disabled to reduce power consumption when only an elapsed seconds count is
required.
15.2
Embedded Characteristics
32-bit Free-running Counter on prescaled slow clock or RTC calibrated 1 Hz clock
16-bit Configurable Prescaler
Interrupt on Alarm
15.3
Block Diagram
Figure 15-1.
Real-time Timer
SLCK
RTPRES
RTTINC
ALMS
16-bit
Prescaler
32-bit
Counter
ALMV
=
CRTV
RTT_MR
RTT_VR
RTT_AR
RTT_SR
RTTINCIEN
RTT_MR
0
1
0
ALMIEN
rtt_int
RTT_MR
set
set
RTT_SR
read
RTT_SR
reset
reset
RTT_MR
reload
rtt_alarm
RTTRST
RTT_MR
RTTRST
RTT_MR
RTTDIS
1
0
RTT_MR
RTC1HZ
RTC 1Hz