ATMEGA1284-MU Atmel, ATMEGA1284-MU Datasheet - Page 171

• Manufacturer Part Number: ATMEGA1284-MU
• Description: IC MCU AVR 128K FLASH 44QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA1284-MU

• 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: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 16K 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-VQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.5.3
8272A–AVR–01/10
SPDR – SPI Data Register
The SPI Data Register is a read/write register used for data transfer between the Register File
and the SPI Shift Register. Writing to the register initiates data transmission. Reading the regis-
ter causes the Shift Register Receive buffer to be read.
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Bit
0x2E (0x4E)
Read/Write
Initial Value
MSB
R/W
7
X
R/W
X
6
R/W
5
X
R/W
X
4
R/W
X
3
R/W
X
2
R/W
X
1
LSB
R/W
X
0
Undefined
SPDR
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