MON08 Multilink User Manual 3
P&EMicrocomputer
Systems, Inc. MON08 MULTILINK
future use. Make sure you do not connect any signal to these lines.
The GND/RST/IRQ connections are standard for debugging all 68HC908
devices.
The OSC pin is added by the MON08 Multilink. The MON08 Multilink
provides the Pin 13 of the MON08 connector with an oscillator frequency of
4.9152 MHz. It may be used to overdrive the target crystal if the target crystal
is of very low frequency.
The Vout pin is added by the MON08 Multilink. 2V, 3V, or 5V is connected to
pin 15 of the MON08 connector.
The MON4-MON8 signals are software configurable to support connections
to different 68HC908 devices. Depending upon the device, either the MON4 or
MON5 pin is the single-wire communications line (which usually corresponds
to PORTA0 or PORTB0). The rest of the lines are either no connect or are port
lines which must be driven to particular values upon reset. The MON08
Multilink software lists the target processor types and their corresponding pin-
outs for user references. The software also selects the single-wire
communications line according to the target processor type.
Specifically, the following figures depict the MON08 connector pin-outs for
the corresponding target processor types:
3.5.1 68HC908AB
Figure 3-1. 68HC908AB Family MON08 Pinout
PORTA0 from the target processor is connected to the MON08 connector Pin
10, acting as the communications line. The user should pull this line up to
target VDD.
PORTC0, PORTC1, and PORTC3 are used for entering monitor mode. By
default the user may bring these signals out to the MON08 connector.
Alternatively, the user may pull up PORTC0 and pull down PORTC1, and pull
up/down PORTC3 for clock division. In which case these signals do not need
to be connected to the MON08 connector.
