User manual

Monitor12 (MON12) User Manual 05/30/01
8
OPERATING INSTRUCTIONS
INTRODUCTION
This chapter provides the necessary information to initialize and operate the
EVB in a target system environment. Information consists of the control switch
description, operating limitations, command line format, monitor commands, and
operating procedures. The operating procedures consist of assembly/disassembly
and downloading descriptions and examples.
RESET SWITCH
The EVB provides a user reset switch. This switch is a momentary action push-
button switch that resets the EVB MCU circuits. Momentary pressing of the switch
will cause the Monitor to restart and the EVB to be re-initialized.
LIMITATIONS
The MCU SCI has been set for 9600 baud using an 8MHz E clock external bus. This
baud rate can be changed by software by re-programming the SC0BDL register in
the ONSCI subroutine of the monitor program.
The RS-232C handshake lines are not used on the COM1 SCI port. A delay of
approximately 100 milliseconds is present between successive characters sent to
terminal computer during the execution of the LOAD command in the monitor
program.
The monitor program will use a portion of the MCU internal RAM resources and may
move internal memory or registers to provide the most complete memory map for
operation. See the EVB board manual for memory mapping details and memory use.
Monitor operation typically requires the external bus to be enabled on the MCU
(Expanded Mode). The MCU external bus requires I/O port use of at least two
ports (16 bits) and some control lines. The MCU expanded bus ports cannot be
applied by the user for I/O functions.
OPERATING PROCEDURES
The EVB is a simplified debugging/evaluating tool designed to operate in either
the debugging or evaluation (emulation) mode of operation.
DEBUGGING MODE
The first mode of operation allows the user to debug user code under control of
the monitor program. User code assembled or compiled on a host computer is
downloaded to the EVB user RAM (see EVB manual for Ram memory location) in
Motorola S-record format (LOAD command). The monitor program is then used to
debug the assembled user code by the use of Breakpoint and Trace command
operations to isolate any code errors. Having the monitor program in EPROM
external to the MCU ($C000-$FFFF) allows the user to add instructions to
customize the monitor for specific requirements.