AT91SAM9G45-CU-999 Atmel, AT91SAM9G45-CU-999 Datasheet - Page 85

• Manufacturer Part Number: AT91SAM9G45-CU-999
• Description: IC MCU ARM9 APMC 324TFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9G45-CU-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 400MHz
• Connectivity: EBI/EMI, Ethernet, I²C, IrDA, MMC, SPI, SSC, UART/USART, USB
• Peripherals: AC'97, DMA, I²S, LCD, POR, PWM, WDT
• Number Of I /o: 160
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: ROM
• Ram Size: 128K x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 1.1 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 324-TFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

13. Real-time Timer (RTT)
13.1
13.2
13.3
Figure 13-1. Real-time Timer
13.4
6438F–ATARM–21-Jun-10
SLCK
RTT_MR
Description
Embedded Characteristics
Block Diagram
Functional Description
RTTRST
reload
Divider
16-bit
RTT_MR
RTPRES
The Real-time Timer is built around a 32-bit counter and used to count elapsed seconds. It gen-
erates a periodic interrupt and/or triggers an alarm on a programmed value.
The Real-time Timer is used to count elapsed seconds. It is built around a 32-bit counter fed by
Slow Clock divided by a programmable 16-bit value. The value can be programmed in the field
RTPRES of the Real-time Mode Register (RTT_MR).
Programming RTPRES at 0x00008000 corresponds to feeding the real-time counter with a 1 Hz
signal (if the Slow Clock is 32.768 kHz). The 32-bit counter can count up to 2
sponding to more than 136 years, then roll over to 0.
• Real-Time Timer, allowing backup of time with different accuracies
RTT_VR
– 32-bit Free-running back-up Counter
– Integrates a 16-bit programmable prescaler running on slow clock
– Alarm Register capable to generate a wake-up of the system through the Shut Down
RTT_AR
RTT_MR
RTTRST
Controller
0
1
Counter
CRTV
32-bit
ALMV
0
RTT_SR
RTT_SR
RTT_SR
=
read
reset
reset
set
set
RTTINC
ALMS
RTTINCIEN
RTT_MR
RTT_MR
ALMIEN
AT91SAM9G45
rtt_alarm
32
seconds, corre-
rtt_int
85