ATMEGA3250-16AUR Atmel, ATMEGA3250-16AUR Datasheet - Page 155

• Manufacturer Part Number: ATMEGA3250-16AUR
• Description: MCU AVR 32K FLASH 16MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

2570M–AVR–04/11
• Bit 5 – DORD: Data Order
When the DORD bit is written to one, the LSB of the data word is transmitted first.
When the DORD bit is written to zero, the MSB of the data word is transmitted first.
• Bit 4 – MSTR: Master/Slave Select
This bit selects Master SPI mode when written to one, and Slave SPI mode when written logic
zero. If SS is configured as an input and is driven low while MSTR is set, MSTR will be cleared,
and SPIF in SPSR will become set. The user will then have to set MSTR to re-enable SPI Mas-
ter mode.
• Bit 3 – CPOL: Clock Polarity
When this bit is written to one, SCK is high when idle. When CPOL is written to zero, SCK is low
when idle. Refer to
marized below:
Table 18-3.
• Bit 2 – CPHA: Clock Phase
The settings of the Clock Phase bit (CPHA) determine if data is sampled on the leading (first) or
trailing (last) edge of SCK. Refer to
functionality is summarized below:
Table 18-4.
• Bits 1, 0 – SPR1, SPR0: SPI Clock Rate Select 1 and 0
These two bits control the SCK rate of the device configured as a Master. SPR1 and SPR0 have
no effect on the Slave. The relationship between SCK and the Oscillator Clock frequency f
shown in the following table:
Table 18-5.
SPI2X
0
0
0
0
1
1
1
1
CPOL
CPHA
0
1
0
1
CPOL Functionality
CPHA Functionality
Relationship Between SCK and the Oscillator Frequency
Figure 18-3
SPR1
0
0
1
1
0
0
1
1
and
Leading Edge
Leading Edge
Figure 18-4
Figure 18-3
Sample
Rising
Falling
Setup
SPR0
0
1
0
1
0
1
0
1
ATmega325/3250/645/6450
for an example. The CPOL functionality is sum-
and
SCK Frequency
f
f
f
f
f
f
f
f
osc
osc
osc
osc
osc
osc
osc
osc
Figure 18-4
/
/
/
/
/
/
/
/
4
16
64
128
2
8
32
64
Trailing Edge
Trailing Edge
for an example. The CPOL
Sample
Falling
Rising
Setup
osc
155
is