AT90USB647-MU Atmel, AT90USB647-MU Datasheet - Page 61

• Manufacturer Part Number: AT90USB647-MU
• Description: MCU, 8BIT, 64K FLASH, USB, 64QFN
• Manufacturer: Atmel

Specifications of AT90USB647-MU

• Controller Family/series: AT90
• No. Of I/o's: 48
• Eeprom Memory Size: 2KB
• Ram Memory Size: 4KB
• Cpu Speed: 16MHz
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 64KB
• Oscillator Type: External, Internal
• Package: 64QFN EP
• Device Core: AVR
• Family Name: AT90
• Maximum Speed: 20 MHz
• Ram Size: 4 KB
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Program Memory Type: Flash
• Number Of Programmable I/os: 48
• Interface Type: SPI/TWI/USART/USB
• On-chip Adc: 8-chx10-bit
• Operating Temperature: -40 to 85 °C
• Number Of Timers: 4
• Lead Free Status / Rohs Status: Details

8.6
8.6.1
7593K–AVR–11/09
Watchdog Reset
MCU Status Register – MCUSR
Figure 8-5.
When the Watchdog times out, it will generate a short reset pulse of one CK cycle duration. On
the falling edge of this pulse, the delay timer starts counting the Time-out period t
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Figure 8-6.
The MCU 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
for details on operation of the Watchdog Timer.
CC
7
–
R
0
Brown-out Reset During Operation
Watchdog Reset During Operation
INTERNAL
TIME-OUT
RESET
RESET
V
CC
6
–
R
0
5
–
R
0
V
CK
4
JTRF
R/W
See Bit Description
BOT-
3
WDRF
R/W
2
BORF
R/W
V
t
TOUT
BOT+
1
EXTRF
R/W
AT90USB64/128
0
R/W
PORF
MCUSR
TOUT
. Refer to
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