Atmel ATmega324PA - Manual (Page 6)

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8152GS–AVR–11/09
ATmega164PA/324PA/644PA/1284P
The ATmega164PA/324PA/644PA/1284P provides the following features: 16/32/64/128K bytes
of In-System Programmable Flash with Read-While-Write capabilities, 512B/1K/2K/4K bytes
EEPROM, 1/2/4/16K 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 sav-
ing 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 main-
tain 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 consump-
tion. 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 ATmega164PA/324PA/644PA/1284P is a powerful microcontroller that provides a
highly flexible and cost effective solution to many embedded control applications.
The ATmega164PA/324PA/644PA/1284P AVR is supported with a full suite of program and sys-
t e m d e v e l o p m e n t t o o l s i n c l u d i n g : C c o m p i l e r s , m a c r o a s s e m b l e r s , p r o g r a m
debugger/simulators, in-circuit emulators, and evaluation kits.
2.2 Comparison Between ATmega164PA, ATmega324PA, ATmega644PA and ATmega1284P
Table 2-1. Differences between ATmega164PA, ATmega324PA and ATmega644PA and
ATmega1284P
Device Flash EEPROM RAM
ATmega164PA 16 Kbyte 512 Bytes 1 Kbyte
ATmega324PA 32 Kbyte 1 Kbyte 2 Kbyte
ATmega644PA 64 Kbyte 2 Kbyte 4 Kbyte
ATmega1284P 128 Kbyte 4 Kbyte 16 Kbyte