atmega169v ATMEL Corporation, atmega169v Datasheet - Page 6

• Manufacturer Part Number: atmega169v
• Description: Atmega169 8-bit With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Port G (PG4..PG0)
RESET
XTAL1
XTAL2
AVCC
AREF
LCDCAP
6
ATmega169/V
buffers have symmetrical drive characteristics with both high sink and source capability.
As inputs, Port F pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port F pins are tri-stated when a reset condition becomes
active, even if the clock is not running. If the JTAG interface is enabled, the pull-up resis-
tors on pins PF7(TDI), PF5(TMS), and PF4(TCK) will be activated even if a reset
occurs.
Port F also serves the functions of the JTAG interface.
Port G is a 5-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port G output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port G pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port G pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port G also serves the functions of various special features of the ATmega169 as listed
on page 70.
Reset input. A low level on this pin for longer than the minimum pulse length will gener-
ate a reset, even if the clock is not running. The minimum pulse length is given in Table
16 on page 38. 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.
AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally
connected to V
nected to V
This is the analog reference pin for the A/D Converter.
An external capacitor (typical > 470 nF) must be connected to the LCDCAP pin as
shown in Figure 98. This capacitor acts as a reservoir for LCD power (V
capacitance reduces ripple on V
value.
CC
through a low-pass filter.
CC
, even if the ADC is not used. If the ADC is used, it should be con-
LCD
but increases the time until VLCD reaches its target
2514PS–AVR–07/06
LCD
). A large