ATMEGA325A-MU Atmel, ATMEGA325A-MU Datasheet - Page 140

• Manufacturer Part Number: ATMEGA325A-MU
• Description: IC MCU AVR 32K FLASH 64VQFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA325A-MU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

17. 8-bit Timer/Counter2 with PWM and Asynchronous Operation
17.1
17.2
17.2.1
140
Features
Overview
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/645
Registers
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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 17-1. 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
17-1. For the actual
clk
TOVn
(Int.Req.)
OCnx
clk
clk
ASY
I/O
I/O
TOSC1
TOSC2
8285B–AVR–03/11