Motorola M68LC302CAF20VCT User Manual page 61

M68ICS08RK In-Circuit Simulator — Rev. 1
MOTOROLA
c. Make sure that the cable is a straight-through cable supporting all
nine pins of the serial port connection.
d. Make sure that no hardware security key or other devices are
attached to the serial port or cable.
e. Make sure that the host PC supports the minimum speed
requirements of the ICS08RKZ software.
f. Make sure to use the correct security code to access the MCU. If the
security bytes have been programmed previously, the part will not
unlock and enter monitor mode unless the correct security code is
sent to the MCU.
g. Check for data at the RKICS end of the serial cable. Pin 3 of this
connector carries RS-232 data into the RKICS; pin 2 carries
RS-232 data out of the RKICS. Pin 4 controls the MCU power. Pin
5 is ground. While the ICS08RKZ software is trying to establish
communications, pins 3 and 4 should both toggle between +10 Vdc
and –10 Vdc (or +12 Vdc and –12 Vdc). If these signals are not seen
at the cable end, the problem is on the PC and cable side of the
system. When connected to the RKICS, a +10 Vdc signal on pin 4
should activate the MCU V
h. Make sure the serial data is getting to the MCU's PTA0 pin. First,
exit any ICS08RKZ software that may be running on the host PC.
Then disconnect power from the RKICS. Ensure that the RKICS
board is configured for the factory default settings. Ensure that
there is an MCU in either XU1, XU2, or XU3 and that it is inserted
correctly. Connect the serial cable between the host PC and the
RKICS. Apply power to the RKICS. Start the ICS08RKZ simulator
software as described in 2.4 Installing the Hardware. Probe the
PTA0 pin (XU1 pin 1, XU2 pin 1, or XU3 pin 2) for the serial data.
Since the board power is turned off and on several times during the
connecting phase, the data observed at the MCU's PTA0 pin is
affected also.
6. Make sure that the MCU has a good clock source. Use an oscilloscope to
check the OSC1 input at the MCU (XU1 pin 8, XU2 pin 8, or XU3
pin 21). Set the oscilloscope to 0.1 ms per division. The oscillator should
run when the MCU power LED is on. Approximately two divisions per
cycle should be observed. This corresponds to a 4.9152-MHz signal, the
Technical Reference and Troubleshooting
Technical Reference and Troubleshooting
Troubleshooting the Start Up
test point and the MCU power LED.
DD
User's Manual
61