ATmega325PA Atmel Corporation, ATmega325PA Datasheet - Page 140

• Manufacturer Part Number: ATmega325PA
• Manufacturer: Atmel Corporation

18. 8-bit Timer/Counter2 with PWM and Asynchronous Operation
18.1
18.2
18.2.1
8285D–AVR–06/11
Features
Overview
Registers
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P
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A simplified block diagram of the 8-bit Timer/Counter is shown in
placement of I/O pins, refer to
including I/O bits and I/O pins, are shown in bold. The device-specific I/O Register and bit loca-
tions are listed in the
Figure 18-1. 8-bit Timer/Counter Block Diagram
The Timer/Counter (TCNT2) and Output Compare Register (OCR2A) are 8-bit registers. Inter-
rupt request (shorten as Int.Req.) signals are all visible in the Timer Interrupt Flag Register
(TIFR2). All interrupts are individually masked with the Timer Interrupt Mask Register (TIMSK2).
TIFR2 and TIMSK2 are not shown in the figure.
Single Compare Unit Counter
Clear Timer on Compare Match (Auto Reload)
Glitch-free, Phase Correct Pulse Width Modulator (PWM)
Frequency Generator
10-bit Clock Prescaler
Overflow and Compare Match Interrupt Sources (TOV2 and OCF2A)
Allows Clocking from External 32kHz Watch Crystal Independent of the I/O Clock
Status flags
Timer/Counter
”Register Description” on page
TCNTn
OCRnx
=
ASSRn
direction
”Pin Configurations” on page
count
clear
BOTTOM
Synchronized Status flags
= 0
Control Logic
=
TCCRnx
TOP
asynchronous mode
0xFF
select (ASn)
154.
clk
Tn
Synchronization Unit
OCnx
(Int.Req.)
Generation
Prescaler
Waveform
2. CPU accessible I/O Registers,
Figure
Oscillator
T/C
18-1. For the actual
OCnx
clk
TOVn
(Int.Req.)
clk
clk
ASY
I/O
I/O
TOSC1
TOSC2
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