atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 52

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

8.0.8
52
ATmega32U4
MCU Status Register – MCUSR
Figure 8-7.
The MCU Status Register provides information on which reset source caused an MCU reset.
• Bit 7..6 - Reserved
These bits are reserved and should be read as 0. Do not set these bits.
• Bit 5– USBRF: USB 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 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 2 – BORF: Brown-out Reset Flag
This bit is set if a Brown-out Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
• Bit 1 – EXTRF: External Reset Flag
This bit is set if an External Reset occurs. The bit is reset by a Power-on Reset, or by writing a
logic zero to the flag.
• Bit 0 – PORF: Power-on Reset Flag
This bit is set if a Power-on Reset occurs. The bit is reset only by writing a logic zero to the flag.
Bit
Read/Write
Initial Value
DM
DP
CC
7
–
R
0
USB Reset During Operation
6
–
R
0
USB Traffic
5
USBRF
R
0
4
JTRF
R/W
See Bit Description
3
WDRF
R/W
2
BORF
R/W
End of Reset
1
EXTRF
R/W
USB Traffic
0
PORF
R/W
MCUSR
7766A–AVR–03/08