ATmega1284P Atmel Corporation, ATmega1284P Datasheet - Page 135

• Manufacturer Part Number: ATmega1284P
• Manufacturer: Atmel Corporation

Specifications of ATmega1284P

• Flash (kbytes): 128 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 20 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 32
• Ext Interrupts: 32
• Usb Speed: No
• Usb Interface: No
• Spi: 3
• Twi (i2c): 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 16
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

16.11.3
8272C–AVR–06/11
TCCRnC – Timer/Counter n Control Register C
When the ICRn is used as TOP value (see description of the WGMn3:0 bits located in the
TCCRnA and the TCCRnB Register), the ICPn is disconnected and consequently the Input Cap-
ture function is disabled.
• Bit 5 – Reserved
This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be
written to zero when TCCRnB is written.
• Bit 4:3 – WGMn3:2: Waveform Generation Mode
See “TCCRnA – Timer/Counter n Control Register A description on page 132.
• Bit 2:0 – CSn2:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter, see
16-10
Table 16-6.
If external pin modes are used for the Timer/Countern, transitions on the Tn pin will clock the
counter even if the pin is configured as an output. This feature allows software control of the
counting.
• Bit 7 – FOCnA: Force Output Compare for Channel A
• Bit 6 – FOCnB: Force Output Compare for Channel B
The FOCnA/FOCnB bits are only active when the WGMn3:0 bits specifies a non-PWM mode.
However, for ensuring compatibility with future devices, these bits must be set to zero when
TCCRnA is written when operating in a PWM mode. When writing a logical one to the
FOCnA/FOCnB bit, an immediate compare match is forced on the Waveform Generation unit.
The OCnA/OCnB output is changed according to its COMnx1:0 bits setting. Note that the
FOCnA/FOCnB bits are implemented as strobes. Therefore it is the value present in the
COMnx1:0 bits that determine the effect of the forced compare.
Bit
(0x82)
Read/Write
Initial Value
CSn2
0
0
0
0
1
1
1
1
and
Figure
CSn1
ATmega164A/PA/324A/PA/644A/PA/1284/P
0
0
1
1
0
0
1
1
Clock Select Bit Description
FOCnA
R/W
7
0
16-11.
CSn0
FOCnB
0
1
0
1
0
1
0
1
R/W
6
0
Description
No clock source (Timer/Counter stopped).
clk
clk
clk
clk
clk
External clock source on Tn pin. Clock on falling edge.
External clock source on Tn pin. Clock on rising edge.
I/O
I/O
I/O
I/O
I/O
R
5
–
0
/1 (No prescaling)
/8 (From prescaler)
/64 (From prescaler)
/256 (From prescaler)
/1024 (From prescaler)
4
–
R
0
R
3
–
0
R
2
–
0
R
1
–
0
R
0
–
0
TCCRnC
Figure
135