ATMEGA328P-20PU Atmel, ATMEGA328P-20PU Datasheet - Page 134

• 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

15.11.3
8025K–AVR–10/09
TCCR1C – Timer/Counter1 Control Register C
When the ICR1 is used as TOP value (see description of the WGM13:0 bits located in the
TCCR1A and the TCCR1B Register), the ICP1 is disconnected and consequently the Input Cap-
ture function is disabled.
• Bit 5 – Reserved Bit
This bit is reserved for future use. For ensuring compatibility with future devices, this bit must be
written to zero when TCCR1B is written.
• Bit 4:3 – WGM13:2: Waveform Generation Mode
See TCCR1A Register description.
• Bit 2:0 – CS12:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter, see
15-10
Table 15-5.
If external pin modes are used for the Timer/Counter1, transitions on the T1 pin will clock the
counter even if the pin is configured as an output. This feature allows software control of the
counting.
• Bit 7 – FOC1A: Force Output Compare for Channel A
• Bit 6 – FOC1B: Force Output Compare for Channel B
The FOC1A/FOC1B bits are only active when the WGM13:0 bits specifies a non-PWM mode.
When writing a logical one to the FOC1A/FOC1B bit, an immediate compare match is forced on
the Waveform Generation unit. The OC1A/OC1B output is changed according to its COM1x1:0
bits setting. Note that the FOC1A/FOC1B bits are implemented as strobes. Therefore it is the
value present in the COM1x1:0 bits that determine the effect of the forced compare.
A FOC1A/FOC1B strobe will not generate any interrupt nor will it clear the timer in Clear Timer
on Compare match (CTC) mode using OCR1A as TOP. The FOC1A/FOC1B bits are always
read as zero.
Bit
(0x82)
Read/Write
Initial Value
CS12
0
0
0
0
1
1
1
1
and
Figure
CS11
0
0
1
1
0
0
1
1
Clock Select Bit Description
FOC1A
R/W
7
0
15-11.
CS10
FOC1B
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 T1 pin. Clock on falling edge.
External clock source on T1 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)
R
4
–
0
R
3
–
0
ATmega48P/88P/168P
R
2
–
0
R
1
–
0
R
0
–
0
TCCR1C
Figure
134