ATMEGA128-16AU SL383 Atmel, ATMEGA128-16AU SL383 Datasheet - Page 146

• Manufacturer Part Number: ATMEGA128-16AU SL383
• Manufacturer: Atmel

8-bit
Timer/Counter2
with PWM
Overview
Registers
146
ATmega128
Timer/Counter2 is a general purpose, single channel, 8-bit Timer/Counter module. The main
features are:
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A simplified block diagram of the 8-bit Timer/Counter is shown in
ment of I/O pins, refer to
I/O bits and I/O pins, are shown in bold. The device-specific I/O register and bit locations are
listed in the
Figure 61. 8-Bit Timer/Counter Block Diagram
The Timer/Counter (TCNT2) and Output Compare Register (OCR2) are 8-bit registers. Interrupt
request (abbreviated to Int.Req. in the figure) signals are all visible in the Timer Interrupt Flag
Register (TIFR). All interrupts are individually masked with the Timer Interrupt Mask Register
(TIMSK). TIFR and TIMSK are not shown in the figure since these registers are shared by other
timer units.
The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on
the T2 pin. The Clock Select logic block controls which clock source and edge the Timer/Counter
uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source
is selected. The output from the clock select logic is referred to as the timer clock (clk
Single Channel Counter
Clear Timer on Compare Match (Auto Reload)
Glitch-free, Phase Correct Pulse width Modulator (PWM)
Frequency Generator
External Event Counter
10-bit Clock Prescaler
Overflow and Compare Match Interrupt Sources (TOV2 and OCF2)
“8-bit Timer/Counter Register Description” on page
Timer/Counter
TCNTn
OCRn
=
“Pin Configurations” on page
direction
BOTTOM
count
clear
= 0
Control Logic
TCCRn
=
TOP
0xFF
clk
2. CPU accessible I/O registers, including
Tn
Generation
Waveform
( From Prescaler )
157.
Figure
Clock Select
Detector
Edge
61. For the actual place-
OCn
(Int.Req.)
2467S–AVR–07/09
TOVn
(Int.Req.)
OCn
Tn
T2
).