5

8011KS–AVR–09/08

ATmega164P/324P/644P

The ATmega164P/324P/644P provides the following features: 16/32/64K bytes of In-System

Programmable Flash with Read-While-Write capabilities, 512B/1K/2K bytes EEPROM, 1/2/4K

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 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. 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 ATmega164P/324P/644P is a powerful microcontroller that provides a highly flexible

and cost effective solution to many embedded control applications.

The ATmega164P/324P/644P AVR is supported with a full suite of program and system devel-

opment tools including: C compilers, macro assemblers, program debugger/simulators, in-circuit

emulators, and evaluation kits.

2.2

Comparison Between ATmega164P, ATmega324P and ATmega644P

Table 2-1.

Differences between ATmega164P and ATmega644P

Device

Flash

EEPROM

RAM

ATmega164P

16 Kbyte

512 Bytes

1 Kbyte

ATmega324P

32 Kbyte

1 Kbyte

2 Kbyte

ATmega644P

64 Kbyte

2 Kbyte

4 Kbyte