ATMEGA1284P-AU Atmel, ATMEGA1284P-AU Datasheet - Page 157
![MCU AVR 128K ISP FLASH 44-TQFP](/photos/6/70/67042/313-44-tqfp_sml.jpg)
ATMEGA1284P-AU
Manufacturer Part Number
ATMEGA1284P-AU
Description
MCU AVR 128K ISP FLASH 44-TQFP
Manufacturer
Atmel
Series
AVR® ATmegar
Datasheets
1.ATMEGA644PA-PU.pdf
(581 pages)
2.ATMEGA644PA-PU.pdf
(32 pages)
3.ATMEGA1284PR231-AU.pdf
(380 pages)
Specifications of ATMEGA1284P-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
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-TQFP, 44-VQFP
Processor Series
ATMEGA128x
Core
AVR8
Data Bus Width
8 bit
Data Ram Size
16 KB
Interface Type
2-Wire, SPI, USART
Maximum Clock Frequency
20 MHz
Number Of Programmable I/os
32
Number Of Timers
3
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, ATAVRRAVEN, ATAVRRZUSBSTICK
Minimum Operating Temperature
- 40 C
On-chip Adc
10 bit, 8 Channel
Package
44TQFP
Device Core
AVR
Family Name
ATmega
Maximum Speed
20 MHz
Operating Supply Voltage
2.5|3.3|5 V
Data Rom Size
4 KB
Height
1.05 mm
Length
10.1 mm
Supply Voltage (max)
5.5 V
Supply Voltage (min)
1.8 V
Width
10.1 mm
Controller Family/series
AVR MEGA
No. Of I/o's
32
Eeprom Memory Size
4KB
Ram Memory Size
16KB
Cpu Speed
20MHz
Rohs Compliant
Yes
For Use With
ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600 - DEV KIT FOR AVR/AVR32
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA1284P-AU
Manufacturer:
ATMEL
Quantity:
1 000
Company:
Part Number:
ATMEGA1284P-AU
Manufacturer:
ATMEL
Quantity:
748
Part Number:
ATMEGA1284P-AU
Manufacturer:
MICROCHIP/微芯
Quantity:
20 000
15.11.3
8059D–AVR–11/09
TCNT2 – Timer/Counter Register
• Bit 6 – FOC2B: Force Output Compare B
The FOC2B bit is only active when the WGM bits specify a non-PWM mode.
However, for ensuring compatibility with future devices, this bit must be set to zero when
TCCR2B is written when operating in PWM mode. When writing a logical one to the FOC2B bit,
an immediate Compare Match is forced on the Waveform Generation unit. The OC2B output is
changed according to its COM2B1:0 bits setting. Note that the FOC2B bit is implemented as a
strobe. Therefore it is the value present in the COM2B1:0 bits that determines the effect of the
forced compare.
A FOC2B strobe will not generate any interrupt, nor will it clear the timer in CTC mode using
OCR2B as TOP.
The FOC2B bit is always read as zero.
• Bits 5:4 – Res: Reserved Bits
These bits are reserved bits in the ATmega1284P and will always read as zero.
• Bit 3 – WGM22: Waveform Generation Mode
See the description in the
• Bit 2:0 – CS22:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter, see
15-9 on page
Table 15-9.
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
Bit
(0xB2)
Read/Write
Initial Value
CS22
0
0
0
0
1
1
1
1
157.
Clock Select Bit Description
R/W
7
0
CS21
0
0
1
1
0
0
1
1
R/W
”TCCR2A – Timer/Counter Control Register A” on page
6
0
CS20
R/W
0
1
0
1
0
1
0
1
5
0
R/W
Description
No clock source (Timer/Counter stopped).
clk
clk
clk
clk
clk
clk
clk
4
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
3
0
R/W
2
0
ATmega1284P
R/W
1
0
R/W
0
0
153.
TCNT2
Table
157