System Initialization; External Reset Button; Abort Button - Motorola M5271EVB User Manual

Operational Procedure
3.2.2

System Initialization

After the EVB is powered-up and initialized, the terminal will display:
Hard Reset
DRAM Size: 16M
ColdFire MCF5271 on the M5271EVB
Firmware vXX.XX.XX (Build X on XXXX)
Copyright 1995-2004 Motorola, Inc.
Enter 'help' for help.
dBUG>
Other means can be used to re-initialize the M5271EVB firmware. These means are
discussed in the following paragraphs.
3.2.2.1

External RESET Button

External RESET (SW3) is the red button. Depressing this button causes all processes to
terminate, resets the MCF5271 processor and board logic and restarts the dBUG firmware.
Pressing the RESET button would be the appropriate action if all else fails.
3.2.2.2

ABORT Button

ABORT (SW2) is the button located next to the RESET button. The abort function causes
an interrupt of the present processing (a level 7 interrupt on MCF5271) and gives control
to the dBUG firmware. This action differs from RESET in that no processor register or
memory contents are changed, the processor and peripherals are not reset, and dBUG is not
restarted. Also, in response to depressing the ABORT button, the contents of the MCF5271
core internal registers are displayed.
The abort function is most appropriate when software is being debugged. The user can
interrupt the processor without destroying the present state of the system. This is
accomplished by forcing a non-maskable interrupt that will call a dBUG routine that will
save the current state of the registers to shadow registers in the monitor for display to the
user. The user will be returned to the ROM monitor prompt after exception handling.
3-4
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M5271EVB User's Manual