ATMEGA48P-20AU Atmel, ATMEGA48P-20AU Datasheet - Page 160

• Manufacturer Part Number: ATMEGA48P-20AU
• Description: MCU AVR 4K ISP FLSH 20MHZ 32TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA48P-20AU

• 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: 23
• Program Memory Size: 4KB (2K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 512 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: 32-TQFP, 32-VQFP
• Processor Series: ATMEGA48x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: I2C/SPI/USART
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• Package: 32TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 20 MHz
• For Use With: ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG770-1005 - ISP 4PORT FOR ATMEL AVR MCU JTAG770-1004 - ISP 4PORT FOR ATMEL AVR MCU SPIATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17.11.3
17.11.4
17.11.5
8025L–AVR–7/10
TCNT2 – Timer/Counter Register
OCR2A – Output Compare Register A
OCR2B – Output Compare Register B
Table 17-9.
If external pin modes are used for the Timer/Counter0, transitions on the T0 pin will clock the
counter even if the pin is configured as an output. This feature allows software control of the
counting.
The Timer/Counter Register gives direct access, both for read and write operations, to the
Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare
Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running,
introduces a risk of missing a Compare Match between TCNT2 and the OCR2x Registers.
The Output Compare Register A contains an 8-bit value that is continuously compared with the
counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OC2A pin.
The Output Compare Register B contains an 8-bit value that is continuously compared with the
counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OC2B pin.
Bit
(0xB2)
Read/Write
Initial Value
Bit
(0xB3)
Read/Write
Initial Value
Bit
(0xB4)
Read/Write
Initial Value
CS22
0
0
0
0
1
1
1
1
Clock Select Bit Description
R/W
R/W
R/W
7
0
7
0
7
0
CS21
0
0
1
1
0
0
1
1
R/W
R/W
R/W
6
0
6
0
6
0
CS20
R/W
R/W
R/W
0
1
0
1
0
1
0
1
5
0
5
0
5
0
R/W
R/W
R/W
Description
No clock source (Timer/Counter stopped).
clk
clk
clk
clk
clk
clk
clk
4
0
4
0
4
0
OCR2A[7:0]
OCR2B[7:0]
TCNT2[7:0]
T2S
T2S
T2S
T2S
T2S
T
T
2
2
S
S
/256 (From prescaler)
/1024 (From prescaler)
/(No prescaling)
/8 (From prescaler)
/32 (From prescaler)
/64 (From prescaler)
/128 (From prescaler)
R/W
R/W
R/W
3
0
3
0
3
0
ATmega48P/88P/168P
R/W
R/W
R/W
2
0
2
0
2
0
R/W
R/W
R/W
1
0
1
0
1
0
R/W
R/W
R/W
0
0
0
0
0
0
OCR2A
OCR2B
TCNT2
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