Datasheet

16.14.2. TC1 Control Register B
Name: TCCR1B
Offset: 0x81
Reset: 0x00
Property: -
Bit 7 6 5 4 3 2 1 0
ICNC1 ICES1 WGM13 WGM12 CS12 CS11 CS10
Access
R/W R/W R/W R/W R/W R/W R/W
Reset 0 0 0 0 0 0 0
Bit 7 – ICNC1: Input Capture Noise Canceler
Writing this bit to '1' activates the Input Capture Noise Canceler. When the noise canceler is activated, the
input from the Input Capture pin (ICP1) is filtered. The filter function requires four successive equal valued
samples of the ICP1 pin for changing its output. The Input Capture is therefore delayed by four Oscillator
cycles when the noise canceler is enabled.
Bit 6 – ICES1: Input Capture Edge Select
This bit selects which edge on the Input Capture pin (ICP1) that is used to trigger a capture event. When
the ICES1 bit is written to zero, a falling (negative) edge is used as trigger, and when the ICES1 bit is
written to '1', a rising (positive) edge will trigger the capture.
When a capture is triggered according to the ICES1 setting, the counter value is copied into the Input
Capture Register (ICR1). The event will also set the Input Capture Flag (ICF1), and this can be used to
cause an Input Capture Interrupt, if this interrupt is enabled.
When the ICR1 is used as TOP value (see description of the WGM1[3:0] bits located in the TCCR1A and
the TCCR1B Register), the ICP1 is disconnected and consequently the Input Capture function is
disabled.
Bits 3, 4 – WGM12, WGM13: Waveform Generation Mode
Refer to TCCR1A.
Bits 0, 1, 2 – CS10, CS11, CS12: Clock Select 1 [n = 0..2]
The three Clock Select bits select the clock source to be used by the Timer/Counter. Refer to Figure
16-10 and Figure 16-11.
Table 16-7. Clock Select Bit Description
CS12 CS11 CS10 Description
0 0 0 No clock source (Timer/Counter stopped).
0 1 clk
I/O
/1 (No prescaling)
0 1 0 clk
I/O
/8 (From prescaler)
0 1 1 clk
I/O
/64 (From prescaler)
1 0 0 clkI/O/256 (From prescaler)
1 0 1 clk
I/O
/1024 (From prescaler)
Atmel ATmega16M1/32M1/64M1 [DATASHEET]
Atmel-8209F-ATmega16M1/32M1/64M1_Datasheet_Complete-10/2016
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