POD–51EH–C541U–12
• © Copyright ICE Technology
5
JP7 (External Code Enable)
This jumper enables access to the external code if the single-chip mode is emulated and part of
the code is mapped into the target code memory. The external code is enabled if the jumper top
is out.
Reset Button
When pressed, this switch resets the pod (including the controller). You can use this button to
recover from a map error status. (See the following “Map Error
LED
” section.)
Reset LED
The Reset
LED
(red
LED
) is turned on whenever the microcontroller reset is active. There are
five possible sources of the controller reset.
1.
Reset from the target starts whenever a low level is detected on the reset pin of the
adapter.
2.
Reset from the S1 button starts by pressing the S1 button on the pod.
3.
Reset from the emulator starts by clicking the reset button in the user interface
EMUL51–PC
Windows software.
4.
Reset from the internal watchdog timer starts if the internal watchdog is enabled, and the
user software does not feed it for a long period.
Note:
It is important to feed the watchdog periodically, otherwise, problems during the
debug process might occur.
5.
During hardware power-down initiated by a low level detected on pin 69 (
HWPD
) of the
target adapter.
6.
When a map error occurs. (See the following “Map Error
LED
” section.)
During all of these reset sequences, the reset
LED
is turned on for a short or long period
depending on the sequence).
Map Error LED
This red
LED
signals a mapping error occurring in this situation. The EA pin from the target
(during the last reset) selects single-chip mode, a code memory address range is mapped to the
target, and there is code access to one of the addresses in this range. This state is illegal. In sin-
gle-chip mode all of the code memory needs to be mapped to the emulator and not to the target,
because the 64K code memory is internal to the C541U controller.
If this illegal state occurs, the Map Error LED turns on simultaneously with the C541U control-
ler entering the reset state, signaling the illegal state. This state is maintained until you push the
reset button. Leaving the map error state is done
only
by pressing the reset button S1 on the
pod. This prevents repetitive occurrences of the illegal state until you fix the problem.
