AT91RM3400-DK Atmel, AT91RM3400-DK Datasheet - Page 157
![KIT DEV FOR AT91RM3400](/photos/9/21/92145/at91rm3400-dk__bottom__sml.jpg)
AT91RM3400-DK
Manufacturer Part Number
AT91RM3400-DK
Description
KIT DEV FOR AT91RM3400
Manufacturer
Atmel
Series
AT91SAM Smart ARMr
Type
MCUr
Datasheets
1.AT91RM3400-DK.pdf
(461 pages)
2.AT91RM3400-DK.pdf
(2 pages)
3.AT91RM3400-DK.pdf
(25 pages)
Specifications of AT91RM3400-DK
Contents
Evaluation Board, Software and Documentation
Processor To Be Evaluated
AT91RM3400
Data Bus Width
32 bit
Interface Type
RS-232, USB
For Use With/related Products
AT91RM3400
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
- Current page: 157 of 461
- Download datasheet (6Mb)
Watchdog Timer
(WDT)
Real-time Timer
(RTT)
1790A–ATARM–11/03
The Watchdog Timer can be used to prevent system lock-up if the software becomes trapped
in a deadlock. It is built around a 16-bit down counter loaded with the value defined in
ST_WDMR (Watchdog Mode Register).
At reset, the value of the ST_WDMR is 0x00020000, corresponding to the maximum value of
the counter. The watchdog overflow signal is tied low during 8 slow clock cycles when a
watchdog overflow occurs (EXTEN bit set in ST_WDMR).
It uses the Slow Clock divided by 128 to establish the maximum watchdog period to be 256
seconds (with a typical slow clock of 32.768 kHz).
In normal operation, the user reloads the Watchdog at regular intervals before the timer over-
flow occurs, by setting the bit WDRST in the ST_CR (Control Register).
If an overflow does occur, the watchdog timer:
•
•
•
•
Writing the ST_WDMR does not reload or restart the down counter. When the ST_CR is writ-
ten the watchdog counter is immediately reloaded from ST_WDMR and restarted and the
Slow Clock 128 divider is also immediately reset and restarted.
Figure 50. Watchdog Timer
The Real-Time Timer is used to count elapsed seconds. It is built around a 20-bit counter fed
by Slow Clock divided by a programmable value. At reset, this value is set to 0x8000, corre-
sponding to feeding the real-time counter with a 1 Hz signal when the Slow Clock is 32.768
Hz. The 20-bit counter can count up to 1048576 seconds, corresponding to more than 12
days, then roll over to 0.
The Real-Time Timer value can be read at any time in the register ST_CRTR (Current Real-
time Register). As this value can be updated asynchronously to the master clock, it is advis-
able to read this register twice at the same value to improve accuracy of the returned value.
This current value of the counter is compared with the value written in the alarm register
ST_RTAR (Real-time Alarm Register). If the counter value matches the alarm, the bit ALMS in
TC_SR is set. The alarm register is set to its maximum value, corresponding to 0, after a reset.
The bit RTTINC in ST_SR is set each time the 20-bit counter is incremented. This bit can be
used to start an interrupt, or generate a one-second signal.
Sets the WDOVF bit in ST_SR (Status Register), from which an interrupt can be
generated.
Generates a pulse for 8 slow clock cycles on the external signal watchdog overflow if the
bit EXTEN in ST_WDMR is set.
Generates an internal reset if the parameter RSTEN in ST_WDMR is set.
Reloads and restarts the down counter.
SLCK
1/128
16-bit Down
WDRST
Counter
WV
RSTEN
EXTEN
AT91RM3400
WDOVF Status
Internal Reset
NWDOVF
157
Related parts for AT91RM3400-DK
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![ATSTK600](/photos/9/20/92038/atstk600_tmb.jpg)
Part Number:
Description:
DEV KIT FOR AVR/AVR32
Manufacturer:
Atmel
Datasheet:
![U641B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
![U4082B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
![U4255BM-M](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
![U4089B-P](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
![TDA4470](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet:
![ATF22V10B-25PC](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
High-performance EE PLD
Manufacturer:
ATMEL Corporation
Datasheet:
![AT89C51ED2-IM](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
8-bit Flash Microcontroller
Manufacturer:
ATMEL Corporation
Datasheet:
![AT24C01](/images/manufacturer_photos/0/0/79/atmel_corporation_tmb.jpg)
Part Number:
Description:
2-Wire Serial EEPROM
Manufacturer:
ATMEL Corporation
Datasheet: