6
8271D–AVR–05/11
ATmega48A/PA/88A/PA/168A/PA/328/P
architecture is more code efficient while achieving throughputs up to ten times faster than con-
ventional CISC microcontrollers.
The ATmega48A/PA/88A/PA/168A/PA/328/P provides the following features: 4K/8Kbytes of In-
System Programmable Flash with Read-While-Write capabilities, 256/512/512/1Kbytes
EEPROM, 512/1K/1K/2Kbytes SRAM, 23 general purpose I/O lines, 32 general purpose work-
ing registers, three flexible Timer/Counters with compare modes, internal and external
interrupts, a serial programmable USART, a byte-oriented 2-wire Serial Interface, an SPI serial
port, a 6-channel 10-bit ADC (8 channels in TQFP and QFN/MLF packages), a programmable
Watchdog Timer with internal Oscillator, and five software selectable power saving modes. The
Idle mode stops the CPU while allowing the SRAM, Timer/Counters, USART, 2-wire Serial Inter-
face, 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 inter-
rupt 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 Reduc-
tion 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.
Atmel
®
offers the QTouch
®
library for embedding capacitive touch buttons, sliders and wheels
functionality into AVR
®
microcontrollers. The patented charge-transfer signal acquisition offers
robust sensing and includes fully debounced reporting of touch keys and includes Adjacent Key
Suppression
®
(AKS
™
) technology for unambiguous detection of key events. The easy-to-use
QTouch Suite toolchain allows you to explore, develop and debug your own touch applications.
The device is manufactured using Atmel’s high density non-volatile memory technology. The
On-chip ISP Flash allows the program memory to be reprogrammed In-System through an SPI
serial interface, by a conventional non-volatile memory programmer, or by an On-chip Boot pro-
gram 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 ATmega48A/PA/88A/PA/168A/PA/328/P is a powerful microcontroller
that provides a highly flexible and cost effective solution to many embedded control applications.
The ATmega48A/PA/88A/PA/168A/PA/328/P AVR is supported with a full suite of program and
system development tools including: C Compilers, Macro Assemblers, Program Debugger/Sim-
ulators, In-Circuit Emulators, and Evaluation kits.
2.2
Comparison Between Processors
The ATmega48A/PA/88A/PA/168A/PA/328/P differ only in memory sizes, boot loader support,
and interrupt vector sizes.
summarizes the different memory and interrupt vector sizes
for the devices.
Table 2-1.
Memory Size Summary
Device
Flash
EEPROM
RAM
Interrupt Vector Size
ATmega48A
4KBytes
256Bytes
512Bytes
1 instruction word/vector
ATmega48PA
4KBytes
256Bytes
512Bytes
1 instruction word/vector
ATmega88A
8KBytes
512Bytes
1KBytes
1 instruction word/vector