Rainbow Electronics ATmega1284P User Manual

Features

• High-performance, Low-power AVR

• Advanced RISC Architecture

– 131 Powerful Instructions – Most Single-clock Cycle Execution
– 32 x 8 General Purpose Working Registers
– Fully Static Operation
– Up to 20 MIPS Throughput at 20 MHz
– On-chip 2-cycle Multiplier

• Nonvolatile Program and Data Memories

– 128K 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

– 4K Bytes EEPROM

Endurance: 100,000 Write/Erase Cycles
– 16K Bytes 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
– Two 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture

Mode
– Real Time Counter with Separate Oscillator
– Six PWM Channels
– 8-channel, 10-bit ADC

Differential mode with selectable gain at 1x, 10x or 200x
– Byte-oriented Two-wire Serial Interface
– Two Programmable Serial USART
– Master/Slave SPI Serial Interface
– Programmable Watchdog Timer with Separate On-chip Oscillator
– On-chip Analog Comparator
– Interrupt and Wake-up on Pin Change

• 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

– 1.8 - 5.5V for ATmega1284P

• Speed Grades

– 0 - 4 MHz @ 1.8 - 5.5V
– 0 - 10 MHz @ 2.7 - 5.5V

– 0 - 20 MHz @ 4.5 - 5.5V

• Power Consumption at 1 MHz, 1.8V, 25°C

– Active: 0.4 mA
– Power-down Mode: 0. 1 µA
– Power-save Mode: 0.7 µA (Including 32 kHz RTC)

®

8-bit Microcontroller

8-bit

Microcontroller
with 128K Bytes
In-System
Programmable
Flash

ATmega1284P

Preliminary

Summary

8059CS–AVR–07/09

1. Pin Configurations

(PCINT8/XCK0/T0) PB0

(PCINT9/CLKO/T1) PB1

(PCINT10/INT2/AIN0) PB2

(PCINT11/OC0A/AIN1) PB3

(PCINT12/OC0B/SS) PB4

(PCINT13/ICP3/MOSI) PB5

(PCINT14/OC3A/MISO) PB6

(PCINT15/OC3B/SCK) PB7

RESET

VCC

GND
XTAL2
XTAL1

(PCINT24/RXD0/T3) PD0

(PCINT25/TXD0) PD1
(PCINT26/RXD1/INT0) PD2
(PCINT27/TXD1/INT1) PD3

(PCINT28/XCK1/OC1B) PD4

(PCINT29/OC1A) PD5

(PCINT30/OC2B/ICP) PD6

PA0 (ADC0/PCINT0)
PA1 (ADC1/PCINT1)
PA2 (ADC2/PCINT2)
PA3 (ADC3/PCINT3)
PA4 (ADC4/PCINT4)
PA5 (ADC5/PCINT5)
PA6 (ADC6/PCINT6)
PA7 (ADC7/PCINT7)
AREF
GND
AVC C
PC7 (TOSC2/PCINT23)
PC6 (TOSC1/PCINT22)
PC5 (TDI/PCINT21)
PC4 (TDO/PCINT20)
PC3 (TMS/PCINT19)
PC2 (TCK/PCINT18)
PC1 (SDA/PCINT17)
PC0 (SCL/PCINT16)
PD7 (OC2A/PCINT31)

PDIP

PA4 (ADC4/PCINT4)
PA5 (ADC5/PCINT5)
PA6 (ADC6/PCINT6)
PA7 (ADC7/PCINT7)
AREF
GND
AVC C
PC7 (TOSC2/PCINT23)
PC6 (TOSC1/PCINT22)
PC5 (TDI/PCINT21)
PC4 (TDO/PCINT20)

(PCINT13/ICP3/MOSI) PB5

(PCINT14/OC3A/MISO) PB6

(PCINT15/OC3B/SCK) PB7

RESET

VCC

GND
XTAL2
XTAL1

(PCINT24/RXD0/T3) PD0

(PCINT25/TXD0) PD1

(PCINT26/RXD1/INT0) PD2

(PCINT27/TXD1/INT1) PD3

(PCINT28/XCK1/OC1B) PD4

(PCINT29/OC1A) PD5

(PCINT30/OC2B/ICP) PD6

(PCINT31/OC2A) PD7

VCC

GND

(PCINT16/SCL) PC0

(PCINT17/SDA) PC1

(PCINT18/TCK) PC2

(PCINT19/TMS) PC3

PB4 (SS/OC0B/PCINT12)

PB3 (AIN1/OC0A/PCINT11)

PB2 (AIN0/INT2/PCINT10)

PB1 (T1/CLKO/PCINT9)

PB0 (XCK0/T0/PCINT8)

GND

VCC

PA0 (ADC0/PCINT0)

PA1 (ADC1/PCINT1)

PA2 (ADC2/PCINT2)

PA3 (ADC3/PCINT3)

TQFP/QFN/MLF

Figure 1-1. Pinout ATmega1284P

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ATmega1284P

Note: The large center pad underneath the QFN/MLF package should be soldered to ground on the

board to ensure good mechanical stability.

8059CS–AVR–07/09

2. Overview

CPU

GND

VCC

RESET

Powe r

Supervision

POR / BOD &

RESET

Watchdog

Oscillator

Watchdog

Timer

Oscillator

Circuits /

Clock

Generation

XTAL1

XTAL2

PORT A (8)

PORT D (8)

PD7..0

PORT C (8)

PC5..0

TWI

SPI

EEPROM

JTAG/OCD

16bit T/C 1

8bit T/C 2

8bit T/C 0

SRAMFLASH

USART 0

Internal

Bandgap reference

Analog

Comparator

A/D

Converter

PA7..0

PORT B (8)

PB7..0

USART 1

TOSC1/PC6TOSC2/PC7

16bit T/C 1

16bit T/C 3

The ATmega1284P 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 ATmega1284P
achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize
power consumption versus processing speed.

2.1 Block Diagram

Figure 2-1. Block Diagram

ATmega1284P

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.

8059CS–AVR–07/09

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The ATmega1284P provides the following features: 128K bytes of In-System Programmable
Flash with Read-While-Write capabilities, 4K bytes EEPROM, 16K bytes SRAM, 32 general pur­pose I/O lines, 32 general purpose working registers, Real Time Counter (RTC), three flexible
Timer/Counters with compare modes and PWM, 2 USARTs, a byte oriented 2-wire Serial Inter­face, a 8-channel, 10-bit ADC with optional differential input stage with programmable gain,
programmable Watchdog Timer with Internal Oscillator, an SPI serial port, IEEE std. 1149.1
compliant JTAG test interface, also used for accessing the On-chip Debug system and program­ming and six software selectable power saving modes. The Idle mode stops the CPU while
allowing the SRAM, Timer/Counters, SPI port, and interrupt system to continue functioning. The
Power-down mode saves the register contents but freezes the Oscillator, disabling all other chip
functions until the next 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 Asynchro­nous 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 On­chip 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. Software 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 ATmega1284P is a powerful microcontroller that provides a highly flexible and cost
effective solution to many embedded control applications.

The ATmega1284P 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.

2.2 Pin Descriptions

2.2.1 VCC

Digital supply voltage.

2.2.2 GND

Ground.

2.2.3 Port A (PA7:PA0)

Port A serves as analog inputs to the Analog-to-digital Converter.

Port A also serves as an 8-bit bi-directional I/O port with internal pull-up resistors (selected for
each bit). The Port A output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port A pins that are externally pulled low will source current if
the 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.

Port A also serves the functions of various special features of the ATmega1284P as listed on

page 79.

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ATmega1284P

8059CS–AVR–07/09

2.2.4 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 ATmega1284P as listed on

page 81.

2.2.5 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.

Port C also serves the functions of the JTAG interface, along with special features of the
ATmega1284P as listed on page 84.

2.2.6 Port D (PD7:PD0)

ATmega1284P

2.2.7 RESET

2.2.8 XTAL1

2.2.9 XTAL2

2.2.10 AVCC

2.2.11 AREF

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 ATmega1284P as listed on

page 87.

Reset input. A low level on this pin for longer than the minimum pulse length will generate a
reset, even if the clock is not running. The minimum pulse length is given in ”System and Reset

Characteristics” on page 328. 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 F and the Analog-to-digital Converter. It should be exter­nally connected to V
to V

through a low-pass filter.

CC

, even if the ADC is not used. If the ADC is used, it should be connected

CC

8059CS–AVR–07/09

This is the analog reference pin for the Analog-to-digital Converter.

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3. Resources

A comprehensive set of development tools, application notes and datasheetsare available for
download on http://www.atmel.com/avr.

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ATmega1284P

8059CS–AVR–07/09