ATMEGA16A-MUR Atmel, ATMEGA16A-MUR Datasheet - Page 41

• Manufacturer Part Number: ATMEGA16A-MUR
• Description: MCU AVR 16KB FLASH 16MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16A-MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

10.3
10.4
10.4.1
8154B–AVR–07/09
Watchdog Timer
Register Description
MCUCSR – MCU Control and Status Register
ADC is used. To reduce power consumption in Power-down mode, the user can avoid the three
conditions above to ensure that the reference is turned off before entering Power-down mode.
The Watchdog Timer is clocked from a separate On-chip Oscillator which runs at 1 MHz. This is
the typical value at V
controlling the Watchdog Timer prescaler, the Watchdog Reset interval can be adjusted as
shown in
dog Timer. The Watchdog Timer is also reset when it is disabled and when a Chip Reset occurs.
Eight different clock cycle periods can be selected to determine the reset period. If the reset
period expires without another Watchdog Reset, the ATmega16A resets and executes from the
Reset Vector. For timing details on the Watchdog Reset, refer to
To prevent unintentional disabling of the Watchdog, a special turn-off sequence must be fol-
lowed when the Watchdog is disabled. Refer to the description of the Watchdog Timer Control
Register for details.
Figure 10-7. Watchdog Timer
The MCU Control and Status Register provides information on which reset source caused an
MCU Reset.
• Bit 4 – JTRF: JTAG Reset Flag
This bit is set if a reset is being caused by a logic one in the JTAG Reset Register selected by
the JTAG instruction AVR_RESET. This bit is reset by a Power-on Reset, or by writing a logic
zero to the flag.
• Bit 3 – WDRF: Watchdog Reset Flag
This bit is set if a Watchdog Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
Bit
Read/Write
Initial Value
Table 10-1 on page
JTD
R/W
7
0
CC
= 5V. See characterization data for typical values at other V
ISC2
R/W
6
0
OSCILLATOR
WATCHDOG
43. The WDR – Watchdog Reset – instruction resets the Watch-
R
5
–
0
JTRF
R/W
4
WDRF
R/W
3
See Bit Description
BORF
R/W
2
page
EXTRF
40.
R/W
1
ATmega16A
PORF
R/W
0
CC
levels. By
MCUCSR
41