ATMEGA644P-A15MZ Atmel, ATMEGA644P-A15MZ Datasheet - Page 372

• 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

372
ATmega164P/324P/644P
16 SPI – Serial Peripheral Interface ......................................................... 161
17 USART ................................................................................................... 171
18 USART in SPI Mode ............................................................................. 199
19 2-wire Serial Interface .......................................................................... 209
16.1
16.2
16.3
16.4
16.5
17.1
17.2
17.3
17.4
17.5
17.6
17.7
17.8
17.9
17.10
17.11
17.12
18.1
18.2
18.3
18.4
18.5
18.6
18.7
18.8
19.1
19.2
19.3
19.4
19.5
19.6
Features ........................................................................................................161
Overview ........................................................................................................161
SS Pin Functionality ......................................................................................166
Data Modes ...................................................................................................166
Register Description ......................................................................................168
Features ........................................................................................................171
USART1 and USART0 ..................................................................................171
Overview ........................................................................................................171
Clock Generation ...........................................................................................173
Frame Formats ..............................................................................................176
USART Initialization .......................................................................................177
Data Transmission – The USART Transmitter ..............................................178
Data Reception – The USART Receiver .......................................................181
Asynchronous Data Reception ......................................................................185
Multi-processor Communication Mode ..........................................................188
Register Description ......................................................................................190
Examples of Baud Rate Setting .....................................................................195
Features ........................................................................................................199
Overview ........................................................................................................199
Clock Generation ...........................................................................................199
SPI Data Modes and Timing ..........................................................................200
Frame Formats ..............................................................................................200
Data Transfer .................................................................................................203
AVR USART MSPIM vs. AVR SPI ................................................................205
Register Description ......................................................................................206
Features ........................................................................................................209
2-wire Serial Interface Bus Definition ............................................................209
Data Transfer and Frame Format ..................................................................210
Multi-master Bus Systems, Arbitration and Synchronization .........................213
Overview of the TWI Module .........................................................................215
Using the TWI ................................................................................................217
7674F–AVR–09/09