Using the STK502 Top Module
STK502 User Guide
2-3
2528A–AVR–11/02
Figure 2-4. 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
PG0
PG2
PG4
NC
GND
PG1
PG3
PG5
RST
VTG
PORTG/RST
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