Features
•
High-performance, Low-power AVR
®
8-bit Microcontroller
•
Advanced RISC Architecture
– 131 Powerful Instructions – Most Single-clock Cycle Execution
– 32 x 8 General Purpose Working Registers
– Fully Static Operation
– Up to 16 MIPS Throughput at 16 MHz
– On-chip 2-cycle Multiplier
Nonvolatile Program and Data Memories
– 32K Bytes of In-System Self-Programmable Flash
Endurance: 10,000 Write/Erase Cycles
– Optional Boot Code Section with Independent Lock Bits
In-System Programming by On-chip Boot Program
True Read-While-Write Operation
– 1024 Bytes EEPROM
Endurance: 100,000 Write/Erase Cycles
– 2K Byte Internal SRAM
– Programming Lock for Software Security
JTAG (IEEE std. 1149.1 Compliant) Interface
– Boundary-scan Capabilities According to the JTAG Standard
– Extensive On-chip Debug Support
– Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
Peripheral Features
– Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes
– One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture
Mode
– Real Time Counter with Separate Oscillator
– Four PWM Channels
– 8-channel, 10-bit ADC
8 Single-ended Channels
7 Differential Channels in TQFP Package Only
2 Differential Channels with Programmable Gain at 1x, 10x, or 200x
– Byte-oriented Two-wire Serial Interface
– Programmable Serial USART
– Master/Slave SPI Serial Interface
– Programmable Watchdog Timer with Separate On-chip Oscillator
– On-chip Analog Comparator
Special Microcontroller Features
– Power-on Reset and Programmable Brown-out Detection
– Internal Calibrated RC Oscillator
– External and Internal Interrupt Sources
– Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby
and Extended Standby
I/O and Packages
– 32 Programmable I/O Lines
– 40-pin PDIP, 44-lead TQFP, and 44-pad QFN/MLF
Operating Voltages
– 2.7 - 5.5V for ATmega32L
– 4.5 - 5.5V for ATmega32
Speed Grades
– 0 - 8 MHz for ATmega32L
– 0 - 16 MHz for ATmega32
Power Consumption at 1 MHz, 3V, 25°C for ATmega32L
– Active: 1.1 mA
– Idle Mode: 0.35 mA
– Power-down Mode: < 1 µA
•
•
•
8-bit
Microcontroller
with 32K Bytes
In-System
Programmable
Flash
ATmega32
ATmega32L
•
•
•
•
•
2503J–AVR–10/06
Pin Configurations
Figure 1.
Pinout ATmega32
PDIP
(XCK/T0) PB0
(T1) PB1
(INT2/AIN0) PB2
(OC0/AIN1) PB3
(SS) PB4
(MOSI) PB5
(MISO) PB6
(SCK) PB7
RESET
VCC
GND
XTAL2
XTAL1
(RXD) PD0
(TXD) PD1
(INT0) PD2
(INT1) PD3
(OC1B) PD4
(OC1A) PD5
(ICP1) PD6
PA0 (ADC0)
PA1 (ADC1)
PA2 (ADC2)
PA3 (ADC3)
PA4 (ADC4)
PA5 (ADC5)
PA6 (ADC6)
PA7 (ADC7)
AREF
GND
AVCC
PC7 (TOSC2)
PC6 (TOSC1)
PC5 (TDI)
PC4 (TDO)
PC3 (TMS)
PC2 (TCK)
PC1 (SDA)
PC0 (SCL)
PD7 (OC2)
TQFP/MLF
PB4 (SS)
PB3 (AIN1/OC0)
PB2 (AIN0/INT2)
PB1 (T1)
PB0 (XCK/T0)
GND
VCC
PA0 (ADC0)
PA1 (ADC1)
PA2 (ADC2)
PA3 (ADC3)
(MOSI) PB5
(MISO) PB6
(SCK) PB7
RESET
VCC
GND
XTAL2
XTAL1
(RXD) PD0
(TXD) PD1
(INT0) PD2
PA4 (ADC4)
PA5 (ADC5)
PA6 (ADC6)
PA7 (ADC7)
AREF
GND
AVCC
PC7 (TOSC2)
PC6 (TOSC1)
PC5 (TDI)
PC4 (TDO)
2
ATmega32(L)
2503J–AVR–10/06
(INT1)
(OC1B)
(OC1A)
(ICP1)
(OC2)
Note:
Bottom pad should
be soldered to ground.
PD3
PD4
PD5
PD6
PD7
VCC
GND
(SCL) PC0
(SDA) PC1
(TCK) PC2
(TMS) PC3
ATmega32(L)
Overview
The ATmega32 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced
RISC architecture. By executing powerful instructions in a single clock cycle, the
ATmega32 achieves throughputs approaching 1 MIPS per MHz allowing the system
designer to optimize power consumption versus processing speed.
Figure 2.
Block Diagram
PA0 - PA7
VCC
PC0 - PC7
Block Diagram
PORTA DRIVERS/BUFFERS
PORTC DRIVERS/BUFFERS
GND
PORTA DIGITAL INTERFACE
PORTC DIGITAL INTERFACE
AVCC
MUX &
ADC
AREF
PROGRAM
COUNTER
ADC
INTERFACE
TWI
STACK
POINTER
TIMERS/
COUNTERS
OSCILLATOR
PROGRAM
FLASH
SRAM
INTERNAL
OSCILLATOR
XTAL1
INSTRUCTION
REGISTER
GENERAL
PURPOSE
REGISTERS
X
WATCHDOG
TIMER
OSCILLATOR
XTAL2
MCU CTRL.
& TIMING
RESET
INSTRUCTION
DECODER
Y
Z
CONTROL
LINES
ALU
INTERRUPT
UNIT
INTERNAL
CALIBRATED
OSCILLATOR
AVR CPU
STATUS
REGISTER
EEPROM
PROGRAMMING
LOGIC
SPI
USART
+
-
COMP.
INTERFACE
PORTB DIGITAL INTERFACE
PORTD DIGITAL INTERFACE
PORTB DRIVERS/BUFFERS
PORTD DRIVERS/BUFFERS
PB0 - PB7
PD0 - PD7
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2503J–AVR–10/06
The AVR core combines a rich instruction set with 32 general purpose working registers.
All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing
two independent registers to be accessed in one single instruction executed in one clock
cycle. The resulting architecture is more code efficient while achieving throughputs up to
ten times faster than conventional CISC microcontrollers.
The ATmega32 provides the following features: 32K bytes of In-System Programmable
Flash Program memory with Read-While-Write capabilities, 1024 bytes EEPROM, 2K
byte SRAM, 32 general purpose I/O lines, 32 general purpose working registers, a
JTAG interface for Boundary-scan, On-chip Debugging support and programming, three
flexible Timer/Counters with compare modes, Internal and External Interrupts, a serial
programmable USART, a byte oriented Two-wire Serial Interface, an 8-channel, 10-bit
ADC with optional differential input stage with programmable gain (TQFP package only),
a programmable Watchdog Timer with Internal Oscillator, an SPI serial port, and six
software selectable power saving modes. The Idle mode stops the CPU while allowing
the USART, Two-wire interface, A/D Converter, SRAM, Timer/Counters, SPI port, and
interrupt system to continue functioning. The Power-down mode saves the register con-
tents but freezes the Oscillator, disabling all other chip functions until the next External
Interrupt or Hardware Reset. In Power-save mode, the Asynchronous Timer continues
to run, allowing the user to maintain a timer base while the rest of the device is sleeping.
The ADC Noise Reduction mode stops the CPU and all I/O modules except Asynchro-
nous Timer and ADC, to minimize switching noise during ADC conversions. In Standby
mode, the crystal/resonator Oscillator is running while the rest of the device is sleeping.
This allows very fast start-up combined with low-power consumption. In Extended
Standby mode, both the main Oscillator and the Asynchronous Timer continue to run.
The device is manufactured using Atmel’s high density nonvolatile memory technology.
The On-chip ISP Flash allows the program memory to be reprogrammed in-system
through an SPI serial interface, by a conventional nonvolatile memory programmer, or
by an On-chip Boot program running on the AVR core. The boot program can use any
interface to download the application program in the Application Flash memory. Soft-
ware in the Boot Flash section will continue to run while the Application Flash section is
updated, providing true Read-While-Write operation. By combining an 8-bit RISC CPU
with In-System Self-Programmable Flash on a monolithic chip, the Atmel ATmega32 is
a powerful microcontroller that provides a highly-flexible and cost-effective solution to
many embedded control applications.
The ATmega32 AVR is supported with a full suite of program and system development
tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit
emulators, and evaluation kits.
Pin Descriptions
VCC
GND
Port A (PA7..PA0)
Digital supply voltage.
Ground.
Port A serves as the analog inputs to the A/D Converter.
Port A also serves as an 8-bit bi-directional I/O port, if the A/D Converter is not used.
Port pins can provide internal pull-up resistors (selected for each bit). The Port A output
buffers have symmetrical drive characteristics with both high sink and source capability.
When pins PA0 to PA7 are used as inputs and are externally pulled low, they will source
current if the internal pull-up resistors are activated. The Port A pins are tri-stated when
a reset condition becomes active, even if the clock is not running.
4
ATmega32(L)
2503J–AVR–10/06
ATmega32(L)
Port B (PB7..PB0)
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port B output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port B pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port B pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port B also serves the functions of various special features of the ATmega32 as listed
on page 57.
Port C (PC7..PC0)
Port C is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port C output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port C pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port C pins are tri-stated when a reset
condition becomes active, even if the clock is not running. If the JTAG interface is
enabled, the pull-up resistors on pins PC5(TDI), PC3(TMS) and PC2(TCK) will be acti-
vated even if a reset occurs.
The TD0 pin is tri-stated unless TAP states that shift out data are entered.
Port C also serves the functions of the JTAG interface and other special features of the
ATmega32 as listed on page 60.
Port D (PD7..PD0)
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port D output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port D pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port D pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port D also serves the functions of various special features of the ATmega32 as listed
on page 62.
RESET
Reset Input. A low level on this pin for longer than the minimum pulse length will gener-
ate a reset, even if the clock is not running. The minimum pulse length is given in Table
15 on page 37. Shorter pulses are not guaranteed to generate a reset.
Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting Oscillator amplifier.
AVCC is the supply voltage pin for Port A and the A/D Converter. It should be externally
connected to V
CC
, even if the ADC is not used. If the ADC is used, it should be con-
nected to V
CC
through a low-pass filter.
AREF is the analog reference pin for the A/D Converter.
XTAL1
XTAL2
AVCC
AREF
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2503J–AVR–10/06
