ATMEGA16U2-MU Atmel, ATMEGA16U2-MU Datasheet - Page 55

• Manufacturer Part Number: ATMEGA16U2-MU
• Description: MCU AVR 16K FLASH USB 32-VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16U2-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Core: AVR8
• Processor Series: ATMEGA16x
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 16 MHz
• Data Ram Size: 1.25 KB
• Data Rom Size: 512 B
• Number Of Programmable I/os: 22
• Number Of Timers: 2
• Mounting Style: SMD/SMT
• Height: 0.95 mm
• Interface Type: SPI, UART
• Length: 5 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 5 mm
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -
• Lead Free Status / Rohs Status: Details

10.5
10.5.1
7799D–AVR–11/10
Register Description
MCUSR – MCU Status Register
Note:
Note: The Watchdog Timer should be reset before any change of the WDP bits, since a change
in the WDP bits can result in a time-out when switching to a shorter time-out period.
The MCU Status Register provides information on which reset source caused an MCU reset.
• Bit 7:6 – Res: Reserved Bit
These bits are reserved and will always read as zero.
Bit
0x34 (0x54)
Read/Write
Initial Value
Assembly Code Example
C Code Example
WDT_Prescaler_Change:
void WDT_Prescaler_Change(void)
{
}
; Turn off global interrupt
cli
; Reset Watchdog Timer
wdr
; Start timed sequence
in
ori
out
; --
; Set new prescaler(time-out) value = 64K cycles (~0.5 s)
ldi
out
; --
; Turn on global interrupt
sei
ret
__disable_interrupt();
__watchdog_reset();
/* Start timed
WDTCSR |= (1<<WDCE) | (1<<WDE);
/* Set new prescaler(time-out) value = 64K cycles (~0.5 s) */
WDTCSR
__enable_interrupt();
1. The example code assumes that the part specific header file is included.
r16, WDTCSR
r16, (1<<WDCE) | (1<<WDE)
WDTCSR, r16
Got four cycles to set the new values from here -
r16, (1<<WDE) | (1<<WDP2) | (1<<WDP0)
WDTCSR, r16
Finished setting new values, used 2 cycles -
= (1<<WDE) | (1<<WDP2) | (1<<WDP0);
R
7
–
0
(1)
(1)
R
6
–
0
equence */
USBRF
R
5
0
R/W
4
–
ATmega8U2/16U2/32U2
WDRF
R/W
3
See Bit Description
BORF
R/W
2
EXTRF
R/W
1
PORF
R/W
0
MCUSR
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