Chapter 3 Monitor Program; Introduction; Program Description; Initialization - Motorola M68HC11EVBU User Manual

3.1

INTRODUCTION

This chapter is a description of the monitor program. This description enables you to understand
the basic structure of the program.
3.2

PROGRAM DESCRIPTION

The BUFFALO (bit user fast friendly aid to logical operations) monitor program is supplied with
the EVBU. The EVBU monitor program is stored in the MCU internal ROM and communicates
via the MCU serial communications interface (SCI). Refer to the buf32.asm file on the EVBU
diskettes for additional information pertaining to the monitor (BUFFALO) program.
The BUFFALO monitor program consists of five parts (or sections) as follows:

1. Initialization

2. Command interpreter
3. I/O routines
4. Utility subroutines
5. Command table
3.2.1 Initialization
This part of BUFFALO contains all of the reset initialization code. In this section, internal RAM
locations are set up, and the I/O channel for the terminal is set up. To set up the terminal I/O port,
BUFFALO must determine if the terminal is connected to the SCI (as in the EVBU) or to an
external ACIA or DUART. This is accomplished by sending a sign-on message to all ports and
then waiting for you to type carriage return <CR> on whichever device is the terminal port.
When BUFFALO recognizes a carriage return from a port, that port is then used for all
subsequent terminal I/O operations. The EVBU terminal device is normally connected to the
SCI.
M68HC11EVBU/D
CHAPTER 3
MONITOR PROGRAM
MONITOR PROGRAM
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