Rainbow Electronics ATmega162V - Manual (Page 105)

105
ATmega162/V
2513E–AVR–09/03
16-bit Timer/Counter
(Timer/Counter1 and
Timer/Counter3)
The 16-bit Timer/Counter unit allows accurate program execution timing (event man-
agement), wave generation, and signal timing measurement. The main features are:
•
True 16-bit Design (i.e., allows 16-bit PWM)
• Two Independent Output Compare Units
• Double Buffered Output Compare Registers
• One Input Capture Unit
• Input Capture Noise Canceler
• Clear Timer on Compare Match (Auto Reload)
• Glitch-free, Phase Correct Pulse Width Modulator (PWM)
• Variable PWM Period
• Frequency Generator
• External Event Counter
• Eight Independent Interrupt Sources (TOV1, OCF1A, OCF1B, ICF1, TOV3, OCF3A, OCF3B,
and ICF3)
Restriction in
ATmega161
Compatibility Mode Note that in ATmega161 compatibility mode, only one 16-bits Timer/Counter is available
(Timer/Counter1).
Overview Most register and bit references in this section are written in general form. A lower case
“n” replaces the Timer/Counter number, and a lower case “x” replaces the Output Com-
pare unit channel. However, when using the register or bit defines in a program, the
precise form must be used i.e., TCNT1 for accessing Timer/Counter1 counter value and
so on.
A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 46. For the
actual placement of I/O pins, refer to “Pinout ATmega162” on page 2. CPU accessible
I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O
Register and bit locations are listed in the “16-bit Timer/Counter Register Description”
on page 127.