The following literature is recommended as an extensive introduction in the area of realtime programming

Preface

Preface

This manual explains how to use the RTX51 Tiny Real-Time Operating System and gives an overview of the functionality of RTX51 Full.  The manual is not a detailed introduction to real-time applications and assumes that you are familiar with Keil C51, A51, the related Utilities, the DOS operating system and the hardware and instruction set of the 8051 microcontrollers.

The following literature is recommended as an extensive introduction in the area of realtime programming:

Deitel, H.M., Operating Systems, second edition, Addison-Wesley Publishing Company, 1990

Ripps, David, A Guide to Real-Time Programming, Englewood Cliffs, N.J, Prentice Hall, 1988/

Allworth, S.T., Introduction to Real-Time Software Design, Springer-Verlag Inc., New York

This user’s guide contains 6 parts:

                                      Part 1:    Overview, describes the functionality of a the RTX51 real-time opeating

systems and discusses the basic features and differences of RTX51 Tiny and

RTX51 Full.  Also included are the technical data of RTX51 Full and

RTX51 Tiny.

                                      Part 2:    Requirements and Definitions, discusses the development tools and the

target system requirements of RTX51 Tiny, explains the terms used in the

the RTX51 Tiny manual and decribes the task definition.

                                      Part 3: Creating RTX51 Tiny Applicaitons, describes the steps necessary to cre-

ate RTX51 Tiny applications.

                                      Part 4:    Library Functions, provides a reference for all RTX51 Tiny library rou-

tines.

                                      Part 5:  System Debugging, describes the stack handling of RTX51 Tiny and con-

tains information about the system debugging.

                                      Part 6: Applications Examples, contains several examples using RTX51 Tiny and

describes the software development process.  This information can be used

as a guideline for your real-time designs.

2                                                                                                                              Contents

OVERVIEW..........................................................................................................7

Introduction ............................................................................................................... 7

Single Task Program.................................................................................................. 8

Round-Robin Program............................................................................................... 8

Round-Robin Scheduling With RTX51..................................................................... 8

RTX51 Events ........................................................................................................... 9

Compiling and Linking with RTX51....................................................................... 11

REQUIREMENTS AND DEFINITIONS ..............................................................15

Development Tool Requirements............................................................................................................ 15

Target System Requirements................................................................................................................... 15

Interrupt Handling ................................................................................................... 15

Reentrant Functions................................................................................................. 16

C51 Library Functions............................................................................................. 16

Usage of Multiple Data Pointers and Arithmetic Units ........................................... 16

Registerbanks........................................................................................................... 17

Task Definition ....................................................................................................................................... 17

Task Management................................................................................................................................... 17

Task Switching ........................................................................................................ 18

Events ...................................................................................................................... 18

CREATING RTX51 TINY APPLICATIONS ........................................................21

RTX51 Tiny Configuration..................................................................................................................... 21

Compiling RTX51 Tiny Programs.......................................................................................................... 23

Linking RTX51 Tiny Programs .............................................................................................................. 23

Optimizing RTX51 Tiny Programs......................................................................................................... 23

RTX51 TINY SYSTEM FUNCTIONS..................................................................25

Function Reference ................................................................................................................................. 26 isr_send_signal.................................................................................................................................. 27 os_clear_signal.................................................................................................................................. 28 Preface

os_create_task....................................................................................................................................29 os_delete_task....................................................................................................................................30 os_running_task_id............................................................................................................................31 os_send_signal...................................................................................................................................32 os_wait...............................................................................................................................................34 os_wait1.............................................................................................................................................36 os_wait2.............................................................................................................................................37

SYSTEM DEBUGGING......................................................................................41

Stack Management...................................................................................................................................41

Debugging with dScope-51......................................................................................................................41

APPLICATION EXAMPLES...............................................................................45

RTX_EX1:  Your First RTX51 Program.................................................................................................45

RTX_EX2:  A Simple RTX51 Application.............................................................................................47

TRAFFIC:  A Traffic Light Controller....................................................................................................49

Traffic Light Controller Commands.........................................................................49

Software ...................................................................................................................49

Compiling and Linking TRAFFIC............................................................................62

Testing and Debugging TRAFFIC ...........................................................................62

Overview

RTX51 is a multitasking real-time operating system for the 8051 family of processors. RTX51 simplifies software design of complex, time-critical projects.

There are two distinct versions of RTX51 available:

                       RTX51 Full               Performs both round-robin and preemptive task switching using up

to four task priorities.  RTX51 works in parallel with interrupt

functions.  Signals and messages may be passed between tasks us-

ing a mailbox system.  You can allocate and free memory from a

memory pool.  You can force a task to wait for an interrupt, time-

out, or signal or message from another task or interrupt.

                       RTX51 Tiny                 Is a subset of RTX51 that will easily run on single-chip 8051 sys-

tems without any external data memory.  RTX51 Tiny supports

many of the features found in RTX51 with the following excep-

tions:  RTX51 Tiny only supports round-robin