The HC08 architecture does not have any built in
functionality to stop a running target. Therefore, in previous scenarios, once
a user had started a target running, there were only three way to regain
control of the MCU:
(1) execute an SWI instruction pre-placed into code,
(2) encounter a breakpoint,
(3) or reset the device.
PEmicro has introduced a feature that will allow method (1)
from above to be expanded to allow the user to stop a running target by issuing
a stop command, rather than pre-planning the point where an SWI will occur.
Please note that the following features are only valid for users who are using
any of the Multilink or Cyclone products for the HC908 family.
When a stop command is issued through the debugger, a
>10ms low pulse will be sent out on the COM line. This allow the user to
poll the COM line in the main loop and issue an SWI when the line goes low.
This feature is always enabled, and is non intrusive to user’s code (if the
user does not use this feature, debugging will not be affected in any way).
The user can also enable an IRQ event to be triggered when a
stop command is issued. This will give the user the added option of creating an
ISR that will execute an SWI instruction when the IRQ event is detected by the
MCU, or polling the IRQ flag and triggering the SWI manually (this will allow
for applications in which interrupts are not used to use this feature). Note
that user’s who are using the IRQ line for other functions should not enable
Please see the attached document for full implementation
guidelines as well as code examples for implementation.