ATMEGA328P-20PU Atmel, ATMEGA328P-20PU Datasheet - Page 157

• Manufacturer Part Number: ATMEGA328P-20PU
• Manufacturer: Atmel

Specifications of ATMEGA328P-20PU

• Cpu Family: ATmega
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: SPI/TWI/USART
• Program Memory Type: Flash
• Program Memory Size: 32KB
• Total Internal Ram Size: 2KB
• # I/os (max): 23
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 6-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 28
• Package Type: PDIP
• Lead Free Status / Rohs Status: Compliant

8025K–AVR–10/09
Note:
Table 17-7
rect PWM mode.
Table 17-7.
Note:
• Bits 3, 2 – Res: Reserved Bits
These bits are reserved bits in the ATmega48P/88P/168P and will always read as zero.
• Bits 1:0 – WGM21:0: Waveform Generation Mode
Combined with the WGM22 bit found in the TCCR2B Register, these bits control the counting
sequence of the counter, the source for maximum (TOP) counter value, and what type of wave-
form generation to be used, see
unit are: Normal mode (counter), Clear Timer on Compare Match (CTC) mode, and two types of
Pulse Width Modulation (PWM) modes (see
Table 17-8.
Notes:
Mode
COM2B1
0
1
2
3
4
5
6
7
0
0
1
1
1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Com-
1. A special case occurs when OCR2B equals TOP and COM2B1 is set. In this case, the Com-
1. MAX= 0xFF
2. BOTTOM= 0x00
WGM2
pare Match is ignored, but the set or clear is done at BOTTOM. See
Mode” on page 149
pare Match is ignored, but the set or clear is done at TOP. See
page 149
shows the COM2B1:0 bit functionality when the WGM22:0 bits are set to phase cor-
0
0
0
0
1
1
1
1
Compare Output Mode, Phase Correct PWM Mode
Waveform Generation Mode Bit Description
COM2B0
for more details.
WGM1
0
1
0
1
0
0
1
1
0
0
1
1
for more details.
Description
Normal port operation, OC2B disconnected.
Reserved
Clear OC2B on Compare Match when up-counting. Set OC2B on
Compare Match when down-counting.
Set OC2B on Compare Match when up-counting. Clear OC2B on
Compare Match when down-counting.
WGM0
Table
0
1
0
1
0
1
0
1
17-8. Modes of operation supported by the Timer/Counter
Timer/Counter
Mode of
Operation
Normal
PWM, Phase
Correct
CTC
Fast PWM
Reserved
PWM, Phase
Correct
Reserved
Fast PWM
”Modes of Operation” on page
ATmega48P/88P/168P
OCRA
OCRA
OCRA
0xFF
0xFF
0xFF
TOP
–
–
(1)
”Phase Correct PWM Mode” on
Immediate
Immediate
Update of
BOTTOM
BOTTOM
OCRx at
TOP
TOP
”Phase Correct PWM
–
–
146).
Set on
TOV Flag
BOTTOM
BOTTOM
MAX
MAX
MAX
TOP
–
–
(1)(2)
157