ATMEGA644P-A15MZ Atmel, ATMEGA644P-A15MZ Datasheet - Page 47

• Manufacturer Part Number: ATMEGA644P-A15MZ
• Description: MCU AVR 64KB FLASH 16MHZ 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644P-A15MZ

• Package / Case: 44-VQFN Exposed Pad
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 32
• Eeprom Size: 2K x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Program Memory Size: 64KB (64K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: I²C, SPI, UART/USART
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.12.2
8.12.3
7674F–AVR–09/09
MCUCR – MCU Control Register
PRR – Power Reduction Register
• Bit 6 – BODS: BOD Sleep
The BODS bit must be written to logic one in order to turn off BOD during sleep, see
on page
BODSE in MCUCR. To disable BOD in relevant sleep modes, both BODS and BODSE must first
be set to one. Then, to set the BODS bit, BODS must be set to one and BODSE must be set to
zero within four clock cycles.
The BODS bit is active three clock cycles after it is set. A sleep instruction must be executed
while BODS is active in order to turn off the BOD for the actual sleep mode. The BODS bit is
automatically cleared after three clock cycles.
• Bit 5 – BODSE: BOD Sleep Enable
BODSE enables setting of BODS control bit, as explained in BODS bit description. BOD disable
is controlled by a timed sequence.
• Bit 7 - PRTWI: Power Reduction TWI
Writing a logic one to this bit shuts down the TWI by stopping the clock to the module. When
waking up the TWI again, the TWI should be re initialized to ensure proper operation.
• Bit 6 - PRTIM2: Power Reduction Timer/Counter2
Writing a logic one to this bit shuts down the Timer/Counter2 module in synchronous mode (AS2
is 0). When the Timer/Counter2 is enabled, operation will continue like before the shutdown.
• Bit 5 - PRTIM0: Power Reduction Timer/Counter0
Writing a logic one to this bit shuts down the Timer/Counter0 module. When the Timer/Counter0
is enabled, operation will continue like before the shutdown.
• Bit 4 - PRUSART1: Power Reduction USART1
Writing a logic one to this bit shuts down the USART1 by stopping the clock to the module.
When waking up the USART1 again, the USART1 should be reinitialized to ensure proper
operation.
• Bit 3 - PRTIM1: Power Reduction Timer/Counter1
Writing a logic one to this bit shuts down the Timer/Counter1 module. When the Timer/Counter1
is enabled, operation will continue like before the shutdown.
Bit
0x35 (0x55)
Read/Write
Initial Value
Bit
(0x64)
Read/Write
Initial Value
41. Writing to the BODS bit is controlled by a timed sequence and an enable bit,
PRTWI
R/W
JTD
R/W
7
0
7
0
PRTIM2
R/W
BODS
6
0
R/W
6
0
PRTIM0
R/W
BODSE
5
0
R/W
5
0
PRUSART1
R/W
4
0
PUD
R/W
4
0
ATmega164P/324P/644P
PRTIM1
R/W
3
0
R
3
–
0
PRSPI
R/W
2
0
R
2
–
0
PRUSART0
IVSEL
R/W
R/W
1
0
1
0
IVCE
R/W
PRADC
0
0
R/W
0
0
Table 8-1
MCUCR
PRR
47