ATmega8A Atmel Corporation, ATmega8A Datasheet - Page 4

• Manufacturer Part Number: ATmega8A
• Manufacturer: Atmel Corporation

Specifications of ATmega8A

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 2
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Pwm Channels: 3
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

2.2
2.2.1
2.2.2
2.2.3
8159D–AVR–02/11
Pin Descriptions
VCC
GND
Port B (PB7:PB0) – XTAL1/XTAL2/TOSC1/TOSC2
The Atmel
isters. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two
independent registers to be accessed in one single instruction executed in one clock cycle. The
resulting architecture is more code efficient while achieving throughputs up to ten times faster
than conventional CISC microcontrollers.
The ATmega8A provides the following features: 8K bytes of In-System Programmable Flash
with Read-While-Write capabilities, 512 bytes of EEPROM, 1K byte of SRAM, 23 general pur-
pose I/O lines, 32 general purpose working registers, three flexible Timer/Counters with
compare modes, internal and external interrupts, a serial programmable USART, a byte oriented
Two-wire Serial Interface, a 6-channel ADC (eight channels in TQFP and QFN/MLF packages)
with 10-bit accuracy, a programmable Watchdog Timer with Internal Oscillator, an SPI serial
port, and five 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 asynchro-
nous 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.
The device is manufactured using Atmel’s high density non-volatile memory technology. The
Flash Program memory can be reprogrammed In-System through an SPI serial interface, by a
conventional non-volatile 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
ATmega8A is a powerful microcontroller that provides a highly-flexible and cost-effective solu-
tion to many embedded control applications.
The Atmel AVR ATmega8A is supported with a full suite of program and system development
tools, including C compilers, macro assemblers, program debugger/simulators, In-Circuit Emula-
tors, and evaluation kits.
Digital supply voltage.
Ground.
Port B is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The
Port B output buffers have symmetrical drive characteristics with both high sink and source
capability. As inputs, Port B pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port B pins are tri-stated when a reset condition becomes active,
even if the clock is not running.
®
AVR
®
AVR core combines a rich instruction set with 32 general purpose working reg-
ATmega8A
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