ATMEGA163 ATMEL [ATMEL Corporation], ATMEGA163 Datasheet - Page 5

• Manufacturer Part Number: ATMEGA163
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Port D (PD7..PD0)
RESET
XTAL1
XTAL2
AVCC
AREF
AGND
Clock Options
Internal RC Oscillator
1142E–AVR–02/03
Port C also serves the functions of various special features of the ATmega163 as listed
on page 124.
Port D is an 8-bit bidirectional I/O port with internal pull-up resistors (selected for each
bit). The Port D output buffers can sink 20 mA. As inputs, Port D pins that are externally
pulled low will source current if the pull-up resistors are activated. Port D also serves the
functions of various special features of the ATmega163 as listed on page 128. The Port
D pins are tristated when a reset condition becomes active, even if the clock is not
running.
Reset input. A low level on this pin for more than 500 ns will generate a Reset, even if
the clock is not running. Shorter pulses are not guaranteed to generate a Reset.
Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting Oscillator amplifier.
This is the supply voltage pin for Port A and the A/D Converter. It should be externally
connected to V
nected to V
ADC.
AREF is the analog reference input pin for the A/D Converter. For ADC operations, a
voltage in the range 2.5V to AVCC can be applied to this pin.
Analog ground. If the board has a separate analog ground plane, this pin should be con-
nected to this ground plane. Otherwise, connect to GND.
The device has the following clock source options, selectable by Flash Fuse bits as
shown:
Table 1. Device Clocking Options Select
Note:
The various choices for each clocking option give different start-up times as shown in
Table 5 on page 25.
The internal RC Oscillator option is an On-chip Oscillator running at a fixed frequency of
nominally 1 MHz. If selected, the device can operate with no external components. The
device is shipped with this option selected. See “EEPROM Read/Write Access” on page
62 for information on calibrating this Oscillator.
Device Clocking Option
External Crystal/Ceramic Resonator
External Low-frequency Crystal
External RC Oscillator
Internal RC Oscillator
External Clock
1. “1” means unprogrammed, “0” means programmed.
CC
through a low-pass filter. See page 105 for details on operation of the
CC
, even if the ADC is not used. If the ADC is used, it should be con-
(1)
ATmega163(L)
1001 - 1000
0100 - 0010
0001 - 0000
1111 - 1010
0111 - 0101
CKSEL3..0
5