ATMEGA103(1999) View Datasheet(PDF) - Atmel Corporation

Part Name

Description

Manufacturer

ATMEGA103
(Rev.:1999)

8-bit Microcontroller with 64K/128K Bytes In-System Programmable Flash

Atmel Corporation 

ATmega603/103

Port E (PE7..PE0)

Port E is an 8-bit bi-directional I/O port with internal pull-up resistors. The Port E output buffers can sink 20 mA. As inputs ,

Port E pins that are externally pulled low will source current if the pull-up resistors are activated.

Port E also serves the functions of various special features.

The port E pins are tri-stated when a reset condition becomes active, even if the clock is not running

Port F (PF7..PF0)

Port F is an 8-bit Input port. Port F also serves as the analog inputs for the ADC.

RESET

Reset input. An external reset is generated by a low level on the RESET pin. Reset pulses longer than 50 ns will generate

a reset, even if the clock is not running. Shorter pulses are not guaranteed to generate a reset.

XTAL1

Input to the inverting oscillator amplifier and input to the internal clock operating circuit.

XTAL2

Output from the inverting oscillator amplifier

TOSC1

Input to the inverting Timer/Counter oscillator amplifier

TOSC2

Output from the inverting Timer/Counter oscillator amplifier

WR

External SRAM Write Strobe.

RD

External SRAM Read Strobe.

ALE

ALE is the Address Latch Enable used when the External Memory is enabled. The ALE strobe is used to latch the low-

order address (8 bits) into an address latch during the first access cycle, and the AD0-7 pins are used for data during the

second access cycle.

AVCC

This is the supply voltage to the A/D Converter. It should be externally connected to VCC via a low-pass filter. See page 66

for details on operation of the ADC.

AREF

This is the analog reference input for the ADC converter. For ADC operations, a voltage in the range AGND to AVCC must

be applied to this pin.

AGND

If the board has a separate analog ground plane, this pin should be connected to this ground plane. Otherwise, connect to

GND.

PEN

This is a programming enable pin for the low-voltage serial programming mode. By holding this pin low during a power-on

reset, the device will enter the serial programming mode. PEN has no function during normal operation.

5

Share Link: