Atmel STK502 manual 2.1 PG0 PG5, 2.2

Using the STK502 Top Module

Figure 2-4. PORTG/RST

1 2

PG0

PG2

PG4

NC

GND

PG1

PG3

PG5

RST VTG

			PORTG/RST
2.2.2.1	PG0 - PG5	These are general I/O ports connected to ZIF socket and the TQFP footprint.
2.2.2.2	RST	On the ATmega169 the RESET-signal and PG5 share the same pin. The “RST” is the
		RESET-signal that comes from the STK500 board. Please note that it is not directly con-
		nected to the ZIF socket or the TQFP footprint on the STK502. This because the

RESET-signal on the STK500 has an pull-up resistor to VCCT which will interfere with

PG5 when used as an ordinary I/O-pin.

￿ If RESET/PG5-pin on ATmega169 shall be used as a Reset pin, the RST and PG5 on the PORTG /RST must be connected with a jumper. See Figure 2-5.

￿ If the pin shall be used as an I/O-pin the jumper must be removed. Figure 2-5.The RESET Signal on PORTG/RST

STK502 User Guide

2-3

2528A–AVR–11/02