ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 136

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

16.11.3
136
Atmel ATmega48PA/88PA/168PA [Preliminary]
TCCR1C – Timer/Counter1 Control Register C
• Bit 5 – Reserved
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
ure 16-10
Table 16-5.
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. There-
fore 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
CS11
0
0
1
1
0
0
1
1
Clock Select Bit Description
Figure
FOC1A
R/W
7
0
16-11.
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
R
2
–
0
R
1
–
0
R
0
–
0
9223B–AVR–09/11
TCCR1C
Fig-