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7810C–AVR–10/12
Atmel ATmega328P [Preliminary]
If external pin modes are used for the Timer/Counter0, transitions on the T0 pin will clock the
counter even if the pin is configured as an output. This feature allows software control of the
counting.
17.11.3
TCNT2 – Timer/Counter Register
The Timer/Counter Register gives direct access, both for read and write operations, to the
Timer/Counter unit 8-bit counter. Writing to the TCNT2 Register blocks (removes) the Compare
Match on the following timer clock. Modifying the counter (TCNT2) while the counter is running,
introduces a risk of missing a Compare Match between TCNT2 and the OCR2x Registers.
17.11.4
OCR2A – Output Compare Register A
The Output Compare Register A contains an 8-bit value that is continuously compared with the
counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OC2A pin.
17.11.5
OCR2B – Output Compare Register B
The Output Compare Register B contains an 8-bit value that is continuously compared with the
counter value (TCNT2). A match can be used to generate an Output Compare interrupt, or to
generate a waveform output on the OC2B pin.
Table 17-9.
Clock Select Bit Description
CS22
CS21
CS20
Description
0
No clock source (Timer/Counter stopped).
00
1
clkT2S/(No prescaling)
01
0
clkT2S/8 (From prescaler)
01
1
clkT2S/32 (From prescaler)
10
0
clkT2S/64 (From prescaler)
10
1
clkT2S/128 (From prescaler)
11
0
clk
T
2S/256 (From prescaler)
11
1
clkT2S/1024 (From prescaler)
Bit
7
65
43
21
0
TCNT2[7:0]
TCNT2
Read/Write
R/W
Initial Value
0
Bit
7
65
43
21
0
OCR2A[7:0]
OCR2A
Read/Write
R/W
Initial Value
0
Bit
7
65
43
21
0
OCR2B[7:0]
OCR2B
Read/Write
R/W
Initial Value
0