6

8271DS–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.

robust sensing and includes fully debounced reporting of touch keys and includes Adjacent Key

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,

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