ATMEGA644A-AU Atmel, ATMEGA644A-AU Datasheet - Page 168

• Manufacturer Part Number: ATMEGA644A-AU
• Description: IC MCU AVR 64K FLASH 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA644A-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8272A–AVR–01/10
Table 17-2.
Figure 17-3. SPI Transfer Format with CPHA = 0
Figure 17-4. SPI Transfer Format with CPHA = 1
164A/164PA/324A/324PA/644A/644PA/1284/1284P
SPI Mode
0
1
2
3
SCK (CPOL = 0)
mode 0
SCK (CPOL = 1)
mode 2
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SCK (CPOL = 0)
mode 1
SCK (CPOL = 1)
mode 3
SAMPLE I
MOSI/MISO
CHANGE 0
MOSI PIN
CHANGE 0
MISO PIN
SS
SS
MSB first (DORD = 0)
LSB first (DORD = 1)
MSB first (DORD = 0)
LSB first (DORD = 1)
SPI Modes
CPOL=0, CPHA=0
CPOL=0, CPHA=1
CPOL=1, CPHA=0
CPOL=1, CPHA=1
Conditions
MSB
LSB
MSB
LSB
Bit 6
Bit 1
Bit 6
Bit 1
Bit 5
Bit 2
Bit 5
Bit 2
Bit 4
Bit 3
Sample (Falling)
Sample (Rising)
Leading Edge
Setup (Falling)
Setup (Rising)
Bit 4
Bit 3
Bit 3
Bit 4
Bit 3
Bit 4
Bit 2
Bit 5
Bit 2
Bit 5
Bit 1
Bit 6
Bit 1
Bit 6
Sample (Falling)
Sample (Rising)
Setup (Falling)
Setup (Rising)
Trailing Edge
LSB
MSB
LSB
MSB
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