ATTIny2313-16MI ATMEL Corporation, ATTIny2313-16MI Datasheet - Page 108

• Manufacturer Part Number: ATTIny2313-16MI
• Description: 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Timer/Counter1 Control
Register B – TCCR1B
108
ATtiny2313/V
• Bit 7 – ICNC1: Input Capture Noise Canceler
Setting this bit (to one) activates the Input Capture Noise Canceler. When the noise can-
celer 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 cap-
ture 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 one, 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 WGM13:0 bits located in
the TCCR1A and the TCCR1B Register), the ICP1 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 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
Figure 48 and Figure 49.
Table 48. Clock Select Bit Description
Bit
Read/Write
Initial Value
CS12
0
0
0
0
1
1
1
1
CS11
0
0
1
1
0
0
1
1
ICNC1
R/W
7
0
CS10
ICES1
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)
WGM13
R/W
4
0
WGM12
R/W
3
0
CS12
R/W
2
0
CS11
R/W
1
0
CS10
R/W
0
0
2543C–AVR–12/03
TCCR1B