4
7674DS–AVR–08/08
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
Automotive
Quality Grade
The ATmega164P/324P/644P have been developed and manufactured according to the most
stringent requirements of the international standard ISO-TS-16949. This data sheet contains
limit values extracted from the results of extensive characterization (Temperature and Voltage).
The quality and reliability of the ATmega164P/324P/644P have been verified during regular
product qualification as per AEC-Q100 grade 1.
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
