OPERATING INSTRUCTIONS
M68HC11EVB/D
4-3
3
4.4 OPERATING PROCEDURES
The EVB is a simplified debugging/evaluating tool designed to operate in either the debugging or
evaluation (emulation) mode of operation. Jumper header J4 is used to determine whether the
BUFFALO monitor prompt will be displayed, or if a jump to internal EEPROM will be executed.
Refer to paragraph 2.3.4 for additional program execution selection information.
Upon reset, the monitor detects the state of the PE0 line. If a low state is detected, the monitor
program is executed and the prompt displayed. If a high state is detected, the monitor will
automatically jump directly to EEPROM (address location $B600) and execute user program
code without displaying the monitor prompt.
4.4.1
Debugging Mode
The first mode of operation allows the user to debug user code under control of the monitor
program. User code can be assembled in one of two methods. The first method is to assemble
code using the line assembler in the BUFFALO monitor program via the EVB user RAM ($C000-
$DFFF). The second method is to assemble code on a host computer and then download the code
to the EVB user RAM via Motorola S-records. The monitor program is then used to debug the
assembled user code. Having the monitor program in EPROM external to the MCU ($E000-
$FFFF) allows the user to add instructions to customize the monitor for specific requirements.
4.4.2
Evaluation Mode
The second mode of operation allows the user to evaluate (emulate) user code in a target system
environment utilizing the memory of the MC68HC11 MCU. This is accomplished by relocating
the code from locations $C000-$DFFF (EVB user RAM) to $E000-$FFFF (MCU 8k ROM).
MCU locations $0000-$00FF (RAM) and $B600-$B7FF (EEPROM) are also available to the
user. The EVB then emulates an EPROM equivalent of the masked ROM device in the single chip
mode of operation. The EVB emulates as if in a single-chip mode of operation, even though
operating in the expanded multiplexed mode of operation at all times.
4.4.3
Monitor Program
The monitor BUFFALO program is the resident firmware for the EVB, which provides a self
contained operating environment. The monitor interacts with the user through predefined
commands that are entered from a terminal. The user can use any of the commands supported by
the monitor.
Summary of Contents for M68HC11EVB
Page 9: ...CONTENTS x M68HC11EVB D ...
Page 35: ...MONITOR PROGRAM 3 8 M68HC11EVB D ...
Page 81: ...OPERATING INSTRUCTIONS 4 46 M68HC11EVB D ...
Page 97: ...SUPPORT INFORMATION 6 12 M68HC11EVB D Figure 6 3 EVB Schematic Diagram Sheet 2 of 2 ...
Page 103: ...APPLICATIONS B 2 M68HC11EVB D Figure B 1 Single Chip Mode Configuration ...