Advertisement
10. Make sure that the MCU can enter and remain in monitor mode. For
11. Make sure that the target circuitry does not interfere with the monitor
M68ICS08ABUM/D
APPENDIX A – TECHNICAL REFERENCE & TROUBLESHOOTING
this to happen, the following conditions must occur:
a. At the rising edge of RST*, the target MCU's IRQ* pin must be at
V
(8.0 Vdc). Using a dual-trace oscilloscope, trigger channel 1
TST
on the rising edge of the MCU's RST* pin and read the IRQ* pin
with channel 2. Start the ICS08ABZ software as described in Sec-
tion 1.6 HARDWARE QUICK START INSTRUCTIONS and
verify that the IRQ* signal is approximately 8.0 Vdc when RST*
rises.
b. At the rising edge of RST*, PTA0, PTC0, PTC1, and PTC3 must
be held at logic values 1, 1, 0, and 0, respectively. The logic levels
are 5.0 V CMOS logic levels (with the factory default setting, and
5.0 Vdc EVDD input or left EVDD input floating) Using a dual-
trace oscilloscope, trigger channel 1 on the rising edge of RST* and
read the corresponding MCU pin with channel 2. PTA0 is the serial
data pin to and from the host PC and should be held at logic value 1
at the rising edge of RST*. PTC0, PTC1, and PTC3 are controlled
by analog switch U5 on the ICS08AB and should be approximately
5.0 V, 0 V, and 0 V respectively, at the rising edge of RST*. After
the rising edge of RST*, the MCU pins PTC0, PTC1, and PTC3
are connected (by the ICS08AB) to the MON08 connector pins
TGT_PTC0, TGT_PTC1, and TGT_PTC3, respectively. The
MCU's PTA0 pin is never connected to the target pins, as it is used
for host communication.
c. IRQ* must remain at 8.0 Vdc to hold the MCU in monitor mode.
The ICS08AB board has an IRQ* lockout feature to keep IRQ* at
8.0 Vdc when the RST* or RST_IN* signal is asserted (low) and
to keep it at 8.0 Vdc until after RST* goes high. The TGT_IRQ*
signal is allowed to control the IRQ* signal when RST* is not
asserted.
mode communications. When connecting target circuitry to the MCU,
be sure to connect the circuits through the ICS08AB by connecting to
the RST_OUT*, RST_IN*, TGT_IRQ*, TGT_PTA0, TGT_PTC0,
TGT_PTC1, and TGT_PTC3 pins of the MON08 connector. These sig-
nals will be connected by the ICS08AB to the corresponding pins of the
MCU through the corresponding MON08 connector pins—RST*,
IRQ*, PTC0, PTC1, and PTC3—after monitor mode is established.
TGT_PTA0 is never connected to PTA0, as the PTA0 signal is being
used for host communications.
A-11
Advertisement
