ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 135

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Timer/Counter1 Control
Register C – TCCR1C
2490G–AVR–03/04
• Bit 6 – ICESn: Input Capture Edge Select
This bit selects which edge on the Input Capture pin (ICPn) that is used to trigger a cap-
ture event. When the ICESn bit is written to zero, a falling (negative) edge is used as
trigger, and when the ICESn bit is written to one, a rising (positive) edge will trigger the
capture.
When a capture is triggered according to the ICESn setting, the counter value is copied
into the Input Capture Register (ICRn). The event will also set the Input Capture Flag
(ICFn), and this can be used to cause an Input Capture Interrupt, if this interrupt is
enabled.
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 Capture 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 TCCRnB is written.
• Bit 4:3 – WGMn3:2: Waveform Generation Mode
See TCCRnA Register description.
• Bit 2:0 – CSn2:0: Clock Select
The three Clock Select bits select the clock source to be used by the Timer/Counter, see
Figure 55 and Figure 56.
Table 62. Clock Select Bit Description
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
Read/Write
Initial Value
CSn2
0
0
0
0
1
1
1
1
CSn1
0
0
1
1
0
0
1
1
FOC1A
W
7
0
CSn0
FOC1B
0
1
0
1
0
1
0
1
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.
FOC1C
I/O
I/O
I/O
I/O
I/O
W
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
ATmega64(L)
R
1
–
0
0
–
R
0
TCCR1C
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