Atmel ATmega32M1 User Manual

259
7647H–AVR–03/12
Atmel ATmega16/32/64/M1/C1
19.2 Typical applications
19.2.1 LIN Current Source
During the configuration of a LIN node in a cluster, it may be necessary to attribute dynamically
an unique physical address to every cluster node. The way to do it is not described in the LIN
protocol.
The Current Source offers an excellent solution to associate a physical address to the applica-
tion supported by the LIN node. A full dynamic node configuration can be used to set-up the LIN
nodes in a cluster.
ATmega16/32/64/M1/C1 proposes to have an external resistor used in conjunction with the Cur-
rent Source. The device measures the voltage to the boundaries of the resistance via the Analog
to Digital converter. The resulting voltage defines the physical address that the communication
handler will use when the node will participate in LIN communication.
In automotive applications, distributed voltages are very disturbed. The internal Current Source
solution of ATmega16/32/64/M1/C1 immunizes the address detection against any kind of volt-
age variations.
Table 19-1. Example of Resistor Values(±5%) for a 8-address System (AV
CC
= 5V
(1)
)
Physical
Address
Resistor Value
R
load
(Ohm)
Typical
Measured
Voltage (V)
Minimum
Reading with
a 2.56V ref
Typical
Reading with
a 2.56V ref
Maximum
Reading with
a 2.56V ref
0 1 000 0.1 40
1 2 200 0.22 88
2 3 300 0.33 132
3 4 700 0.47 188
4 6 800 0.68 272
5 10 000 1 400
6 15 000 1.5 600
7 22 000 2.2 880

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