ATmega48PA/88PA/168PA/328P
architecture is more code efficient while achieving throughputs up to ten times faster than con-
ventional CISC microcontrollers.
The ATmega48PA/88PA/168PA/328P provides the following features: 4K/8K bytes of In-System
Programmable Flash with Read-While-Write capabilities, 256/512/512/1K bytes EEPROM,
512/1K/1K/2K bytes SRAM, 23 general purpose I/O lines, 32 general purpose working registers,
three flexible Timer/Counters with compare modes, internal and external interrupts, a serial pro-
grammable 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 Interface, 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 dur-
ing 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.
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 ATmega48PA/88PA/168PA/328P is a powerful microcontroller that
provides a highly flexible and cost effective solution to many embedded control applications.
The ATmega48PA/88PA/168PA/328P 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
Comparison Between ATmega48PA, ATmega88PA, ATmega168PA and ATmega328P
The ATmega48PA, ATmega88PA, ATmega168PA and ATmega328P differ only in memory
sizes, boot loader support, and interrupt vector sizes.
Table 2-1
summarizes the different mem-
ory and interrupt vector sizes for the three devices.
Table 2-1.
Device
ATmega48PA
ATmega88PA
ATmega168PA
ATmega328P
Memory Size Summary
Flash
4K Bytes
8K Bytes
16K Bytes
32K Bytes
EEPROM
256 Bytes
512 Bytes
512 Bytes
1K Bytes
RAM
512 Bytes
1K Bytes
1K Bytes
2K Bytes
Interrupt Vector Size
1 instruction word/vector
1 instruction word/vector
2 instruction words/vector
2 instruction words/vector
ATmega88PA, ATmega168PA and ATmega328P support a real Read-While-Write Self-Pro-
gramming mechanism. There is a separate Boot Loader Section, and the SPM instruction can
only execute from there. In ATmega48PA, there is no Read-While-Write support and no sepa-
rate Boot Loader Section. The SPM instruction can execute from the entire Flash.
6
8161D–AVR–10/09
ATMEL [ ATMEL CORPORATION ]
