Atmel ATmega32M1 User Manual

107
7647H–AVR–03/12
Atmel ATmega16/32/64/M1/C1
13. 16-bit Timer/Counter1 with PWM
The 16-bit Timer/Counter unit allows accurate program execution timing (event management),
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
• Retriggering Function by External Signal (ICP1A or ICP1B)
• Clear Timer on Compare Match (Auto Reload)
• Glitch-free, Phase Correct Pulse Width Modulator (PWM)
• Variable PWM Period
• Frequency Generator
• External Event Counter
• Four independent interrupt Sources (TOV1, OCF1A, OCF1B, and ICF1)
13.1 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 Compare 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 13-1. For the actual
placement of I/O pins, refer to “Pin Descriptions” on page 5. 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 loca-
tions are listed in the “16-bit Timer/Counter Register Description” on page 130.
The PRTIM1 bit in “Power Reduction Register” on page 42 must be written to zero to enable
Timer/Counter1 module.

Atmel ATmega32M1 Specifications

General

Architecture	8-bit AVR
Flash Memory	32 KB
SRAM	2 KB
EEPROM	1 KB
Clock Speed	16 MHz
GPIO Pins	32
I/O Pins	32
ADC Channels	8
ADC Resolution	10-bit
UART	1
USART	1
SPI	1
I2C	1
PWM Channels	6
CAN	1
Operating Voltage	2.7V - 5.5V
Operating Temperature	-40°C to +85°C
Temperature Range	-40°C to +85°C
Package	44-TQFP, 44-QFN

Summary

Features

AVR CPU Core

Reset and Interrupt Handling

Explanation of interrupt sources, vectors, priority levels, and behavior during interrupt execution.

System Clock

System Clock Prescaler

Details on the CLKPR register for dividing the system clock to reduce power consumption and affect peripheral frequencies.

Power Management and Sleep Modes

8-bit Timer/Counter0 with PWM

Modes of Operation

Detailed explanation of Normal, CTC, and various PWM modes for Timer/Counter0 operation.

Controller Area Network - CAN

CAN Protocol

Explanation of the CAN protocol principles, standards, and message transmission priorities.

Error Management

Description of error detection mechanisms (message and bit level) and fault confinement states.

Analog to Digital Converter - ADC

Features

List of ADC capabilities including resolution, accuracy, conversion time, input channels, and reference voltages.

Starting a Conversion

Procedures for initiating ADC conversions, including single conversion and auto-triggering modes.

debugWIRE On-chip Debug System

Features

Overview of debugWIRE capabilities including program flow control, real-time operation, and symbolic debugging.

Boot Loader Support – Read-While-Write Self-Programming ATmega16/32/64/M1/C1

Self-Programming the Flash

Procedures and considerations for programming the Flash memory using the SPM instruction.

Memory Programming

Program And Data Memory Lock Bits

Fuse Bits

Electrical Characteristics

Absolute Maximum Ratings*

Critical voltage, current, and temperature limits that must not be exceeded for device reliability.

DC Characteristics

Instruction Set Summary

Register Summary