Multisim MCU Module User Guide

Multisim MCU Module User Guide
Multisim™ MCU Module
User Guide
January 2007
374486A-01
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When this guide refers to a toolbar button, an image of the button appears in the left column.
This guide uses the convention Menu/Item to indicate menu commands. For example, “File/Open” means
choose the Open command from the File menu.
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The Multisim Documentation Set
Multisim documentation consists of a User Guide, the Component Reference Guide and online help. All
Multisim users receive PDF versions of the User Guide and the Component Reference Guide.
The Multisim MCU Module User Guide describes the functions specific to Multisim’s MCU module.
You should also refer to Getting Started with NI Circuit Design Suite.
Online Help
Multisim offers a full helpfile system to support your use of the product.
Choose Help/Multisim Help to display the helpfile that explains the Multisim program in detail, or choose
Help/Component Reference to display the helpfile that contains details on the components families provided
with Multisim. Both are compiled HTML helpfiles, offering a table of contents and index.
In addition, you can display context-sensitive help by pressing F1 from any command or window, or by
clicking the Help button on any dialog box that offers it.
Table of Contents
1. Introduction
1.1
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2
Multisim MCU Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3
Debugging Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.4
Multisim MCU Module Source Code Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.5
MCU Memory View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.6
Advanced Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
1.7
Peripheral Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
2. Multisim MCU Module File Management
2.1
MCU Design Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
2.2
MCU Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3
2.3
Adding and Removing Projects, Folders and Files . . . . . . . . . . . . . . . . . . . . . . . . . . 2-4
3. Multisim MCU Module Code Manager
3.1
MCU Code Manager Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
3.2
Adding and Removing Projects, Folders and Files in the MCU Code Manager . . . . 3-3
3.3
MCU Project Build Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3
3.3.1
8051 Workspace Build Settings Example . . . . . . . . . . . . . . . . . . . . . . . . . . 3-5
3.3.2
Loading an External Hex File Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
3.4
Building an MCU Workspace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-11
3.4.1
Errors and Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12
3.4.2
Simulation of Machine Code File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-13
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4. Multisim MCU Module Source Code Editor
4.1
Opening a Source Code File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.2
Building Source Code Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
4.3
Source Code View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
5. Multisim MCU Module Debugging Features
5.1
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
5.2
Opening a Debug View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
5.3
Debug Window Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
5.4
Simulation Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.5
Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
5.6
Stepping and Breaking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
5.7
Memory View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
Appendix A - Multisim MCU Module Parts
A.1
8051/8052 Microcontroller Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1
A.2
PIC16F84/16F84A Microcontroller Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-3
A.3
RAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-4
A.4
ROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-5
Appendix B - Support and Services
B.1
Technical Support and Professional Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1
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Chapter 1
Introduction
The following are found in this chapter.
1.1
Subject
Page No.
Overview
1-1
Multisim MCU Basics
1-2
Debugging Tools
1-2
Multisim MCU Module Source Code Editor
1-3
MCU Memory View
1-3
Advanced Features
1-3
Peripheral Devices
1-3
Overview
The Multisim MCU module is an add-on to Multisim, the schematic capture and simulation
application of National Instruments Circuit Design Suite.
Microcontroller (MCU) components are useful for many circuit designs. A modern
microcontroller typically combines a CPU, data memory, program memory, and peripheral
devices on a single physical chip. The integration of these essential elements of a computer
into a single chip reduces component counts and board size resulting in higher reliability with
more capabilities. The Multisim MCU module’s co-simulation system provides software
development features for writing and debugging code for embedded devices.
Embedded software development can be a challenging process for even the best
programmers. Multisim MCU helps you produce high quality code more quickly and easily.
The MCU development interfaces allow you to pause a simulation, inspect the internal
memory and registers of the MCU, set code breakpoints and single step through your code.
 National Instruments Corporation
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Multisim MCU User Guide
Introduction
Note Refer to Getting Started with NI Circuit Design Suite for a tutorial covering
Multisim MCU’s main functions.
1.2
Multisim MCU Basics
This and subsequent sections give a brief overview of the Multisim MCU module’s
functionality.
To place an MCU:
1. Select Place/Component to display the Select a Component dialog box.
2. Navigate to the MCU Module Group and select the Family containing the desired MCU
(e.g., 805x, PIC).
3. Select the desired MCU, click OK and click again to place the component on the
workspace. The MCU Wizard dialog appears. The MCU Wizard helps you get started by
creating an MCU Workspace, default project and source file.
4. Complete the steps in the wizard as detailed in “2.2 MCU Wizard” on page 2-3.
5. Use the MCU Code Manager to manage the MCU files in your MCU workspace and to set
the build settings for your MCU project. See “3.1 MCU Code Manager Overview” on
page 3-1 for details.
1.3
Debugging Tools
The Multisim MCU Module’s debugging tools give you the ability to control execution at the
instruction level while also providing views of the memory and registers within the MCU.
After an MCU's project has been built (without errors) using the Build command, the debug
window becomes accessible.
To open the debug window for a particular MCU, select MCU/<MCU name, e.g., MCU 8051
U1>/Debug View.
This opens a new window in Multisim with a drop-down list at the top used to select between
the different views.
There is one view available for each source code file, as well as one for the disassembly of the
entire project. By default, opening a Debug View opens the project disassembly view which is
a complete disassembly of the ROM for the relevant MCU. In the project disassembly view,
every memory address is shown from address zero to the maximum address of the ROM. The
project disassembly view always shows the disassembly (not the listing assembly) because it
shows memory addresses which may not have a corresponding listing (such as the opcodes
from statically linked libraries).
For details on debugging, see Multisim MCU Module Debugging Features on page 5-1.
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Multisim MCU Module Source Code Editor
1.4
Multisim MCU Module Source Code Editor
The source code view shows the assembly or C source code for the MCU program.
The numbers on the far left are the program memory addresses and the hexadecimal codes to
their immediate right are the assembled codes for each mnemonic assembly instruction. The
column of numbers in the middle shows the line number in the original assembly or C source.
The remainder of the line to the right shows the assembly source and comments.
1.5
MCU Memory View
The contents of the MCU Memory View change depending on the type of MCU. It may, for
example, contain internal memory information, register views and configuration information.
For details on specific MCUs, see “A.1 8051/8052 Microcontroller Units” on page A-1 and
“A.2 PIC16F84/16F84A Microcontroller Units” on page A-3.
1.6
Advanced Features
The Multisim MCU Module provides advanced debugging tools to make it easy to pause your
circuit and explore the internal data and state of the MCU controlling your circuit. You can set
breakpoints and single step through assembly code while validating that the register contents
are changing as expected. You can also manually edit most memory views while debugging.
An example of the Multisim MCU Module’s advanced debugging features is found in Getting
Started with NI Circuit Design Suite.
1.7
Peripheral Devices
Along with its selection of MCUs, Multisim MCU contains a number of peripheral devices.
The MCU Module Group contains RAM and ROM devices that are designed to function
specifically with the MCUs. For details on these components, see “A.3 RAM” on page A-4
and “A.4 ROM” on page A-5.
The Advanced Peripherals Group contains a selection of Keypads, LCDs, Terminals and
Miscellaneous Peripherals like the Liquid Holding Tank.
For details, refer to the Multisim Component Reference Guide, or the component helpfile.
 National Instruments Corporation
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Chapter 2
Multisim MCU Module File Management
This chapter describes the file management features used in the Multisim MCU module.
The following are described in this chapter.
2.1
Subject
Page No.
MCU Design Overview
2-1
MCU Wizard
2-3
Adding and Removing Projects, Folders and Files
2-4
MCU Design Overview
Every MCU component that is placed on the circuit schematic is associated with an MCU
design consisting of a set of MCU files that exist on your hard disk separate from the
Multisim circuit file (*.ms10):
MCU File Type
File Extension
Description
MCU workspace
file
.mcuws
Maintains information on projects contained in the MCU
workspace.
MCU project file
.mcuprj
Maintains information on files contained in the MCU project.
Assembly
source file
.asm
Assembly code
Assembly
include file
.inc
Assembly code
C source file
.c
C code
C header file
.h
C code
 National Instruments Corporation
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Multisim MCU Module File Management
Each MCU workspace file is contained inside a workspace folder with the same name as the
workspace file. All the other MCU-related files for this particular MCU component are stored
inside the MCU workspace file in a hierarchical manner.
Each MCU project has its own project folder inside the workspace folder. Each MCU project
file resides inside the project folder and the name of the project folder is the same as the
project file. The assembly and C files are contained inside the project folder and also can be
stored inside additional folders nested inside the project folder.
Below is an example of a circuit (Circuit1) in Multisim. It contains an 8051 MCU
component (U1) that has an MCU design in the MCU workspace 8051workspace as
shown in the Design Toolbox view. The MCU workspace contains two projects, project1
and project2. Project1 has some MCU files, but project2 is empty.
MCU component U1 with associated MCU workspace
shown in the Design Toolbox in the left pane
The MCU files for the above circuit are organized on disk in the following file structure:
The arrows point to the contents contained in the project1 and folder1 folders.
Multisim stores the path to the MCU workspace file inside the circuit file (*.ms10). Every
time Circuit1.ms10 is opened, the MCU workspace must be found on disk in order for
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MCU Wizard
Multisim to load the MCU design and display it in the Design Toolbox or perform any actions
on the MCU workspace.
2.2
MCU Wizard
The MCU Wizard helps you get started by creating an MCU Workspace, default project and
source file.
To invoke the MCU Wizard:
1. Select Place/Component to display the Select a Component dialog box.
2. Navigate to the MCU Module Group and select the Family containing the desired MCU
(e.g., 805x, PIC).
3. Select the desired MCU, click OK and click again to place the component on the
workspace. Step 1 of the MCU Wizard dialog appears. This is where you specify the MCU
workspace information.
4. Complete the following as desired:
• ...workspace path for this MCU — specifies where the workspace folder will be created.
Or, click Browse and navigate to the desired location.
• ...workspace name — the name of the folder and the name of the MCU workspace file
inside the workspace folder.
5. Click Next to display step 2 of the MCU Wizard. This is where you specify the project
information.
6. Complete the following as desired:
• Project type — choose one of: Standard - this project type contains source code files
that needs to be built in order to create a machine code (intel hex) file to load into the
MCU at the start of simulation; Load External Hex File - this project type contains no
files and does not need a build step.
• Programming language — active for standard Project type only. Select C or Assembly.
• Assembler/compiler tool — active for standard Project type only.
• Project name — the name of the project file and the project folder that will be created
inside the MCU workspace folder.
7. Click Next to display step 3 of the MCU Wizard. This is where you specify the source file
that you want to create for the project.
8. Complete the following as desired:
• Create empty project — select if you do not wish to create a source file.
• Add source file — enable if you wish to create a source file.
• Enter the name of the source file — becomes active when Add source file is enabled. Can
be an assembly or C file.
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Multisim MCU Module File Management
9. Click Finish to close the MCU Wizard and create the MCU related files for the MCU
component.
Note If you select Cancel at any time, no MCU workspace is created and the MCU
component is removed from the circuit schematic.
2.3
Adding and Removing Projects, Folders and
Files
After you place the MCU component and create the MCU workspace, project and file, you
can add or remove any projects and/or MCU files to the MCU design.
To manipulate items in the MCU design:
1. Right-click on an MCU item in the Design Toolbox. The contents of the pop-up menu that
appears vary depending on the MCU item type that you clicked, as detailed below:
MCU Item Type
Right-click Context Menu Items
MCU workspace
Add MCU Project…
MCU project
Add New MCU Source File…
Add Existing MCU Source File…
Add MCU Source Folder…
Remove MCU Project
Set Active MCU Project
MCU source file
Remove MCU Source File From Project
MCU source folder
Add MCU Source File…
Add Existing MCU Source File…
Add MCU Source Folder…
Remove MCU Source Folder
2. Select the desired menu item
Add MCU Project — displays a dialog box where you specify the Project Type that you
want to create (standard/load external hex file) and the Project Name. The new project is
created in the MCU Workspace folder of the MCU workspace that you right-clicked in the
Design Toolbox.
Add New MCU Source File — displays a dialog box where you select the File type
(assembly file (.asm), assembly include file (.inc), C source file (.c), or C header file
(.h)), and enter the Filename. The file is created in the MCU project folder or MCU
source folder that you right-clicked in the Design Toolbox.
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Adding and Removing Projects, Folders and Files
Add Existing MCU Source File — displays a file browser where you select an existing
source file. The selected file is copied to the MCU project folder or source folder that was
selected in the Design Toolbox.
Add MCU Source Folder — adds an MCU folder to the MCU project folder or source
folder that you right-clicked in the Design Toolbox.
Remove MCU Project — removes the selected MCU project from the MCU workspace.
Remove MCU Source File From Project — removes the selected source file (*.asm,
*.inc, *.c, *.h) from the MCU design.
Remove MCU Source Folder — removes the selected folder from the MCU design.
Set Active MCU Project — sets the selected MCU Project to be the active project. The
active project in the Design Toolbox for an MCU workspace, has a blue colored square in
the icon next to it. Any build operation applied to an MCU instance uses this project’s
files. The results of the build on the active project are also used for simulating the circuit.
Note Each file manipulation command that appears in the right-click context menus also
appears in the MCU Code Manager (see “3.1 MCU Code Manager Overview” on
page 3-1 for details).
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Chapter 3
Multisim MCU Module Code Manager
This chapter describes the Multisim MCU module’s MCU Code Manager.
The following are described in this chapter.
3.1
Subject
Page No.
MCU Code Manager Overview
3-1
Adding and Removing Projects, Folders and
Files in the MCU Code Manager
3-3
MCU Project Build Settings
8051 Workspace Build Settings Example
Loading an External Hex File Project
3-3
3-5
3-10
Building an MCU Workspace
Errors and Warnings
Simulation of Machine Code File
3-11
3-12
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MCU Code Manager Overview
The MCU Code Manager dialog box lets you manage the MCU files in an MCU workspace
and enter the build settings for each MCU project. Each MCU project has a number of build
settings that consist of assembler/compiler tool information, the command line options to be
used with the selected tool, and additional information on the intermediate/output files to
generate during a build, and where the tools/files are located.
To access the MCU Code Manager for a specific MCU:
1. Select MCU/<MCU name, e.g., MCU 8051 U1>/MCU Code Manager.
Or
Right-click on the MCU workspace in the Design Toolbox and select MCU Code Manager
from the pop-up that displays.
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Multisim MCU Module Code Manager
Note The MCU menu displays all instances of MCUs in a circuit design. In the example
below, there is only one MCU “U1”.
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Adding and Removing Projects, Folders and Files in the MCU Code Manager
The above shows the contents of the MCU Code Manager for MCU U1 from the previous
screen capture. Project1 is an 8051 Metalink assembler project that has only one tab
(General) in its project build settings.
3.2
Adding and Removing Projects, Folders and
Files in the MCU Code Manager
After you place the MCU component and create the MCU workspace, project and file, you
can add or remove any projects or MCU files in the MCU design.
The buttons in the MCU Code Manager located below the tree display of the MCU workspace
correspond to the file manipulation commands that display in the right-click context menus of
MCU items in the Design Toolbox.
To manipulate items in the MCU design from the MCU Code Manager:
1. Click the New MCU Project, New File, New Folder or Files buttons to display the same
dialog boxes as the right-click context menu commands Add MCU Project, Add New MCU
Source File, Add MCU Source Folder, and Add Existing MCU Source File. For details, see
“2.3 Adding and Removing Projects, Folders and Files” on page 2-4.
To remove an item from the MCU workspace tree view:
1. Highlight the desired item in the tree and click Remove Selected.
Note You cannot remove the MCU workspace.
To select a different active project:
1. Select another project from the Active Project drop-down list.
To select the external ROM into which to load the MCU’s machine code:
1. Select the desired ROM from the XROM used by MCU drop-down list.
Note There are no XROMs in the example in “3.1 MCU Code Manager Overview” on
page 3-1, but if there was and an XROM part was selected, the Load machine code
(*.hex) file only… checkbox would be enabled to let you could control how to load the
machine code into the XROM for simulation.
3.3
MCU Project Build Settings
Each MCU project in an MCU design has its own build settings that can be different from
other projects inside the same workspace. The build settings available are different for each
assembler or compiler tool that is supported by Multisim. The tools supported by Multisim
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are the 8051 Metalink Assembler, the Microchip PIC Assembler, the Hi-Tech 8051 C Lite
compiler and the Hi-Tech PICC Lite compiler.
To configure the build settings, use the tabs that appear on the right of the MCU Code Manager
dialog box. The tabs that appear, and their content, correspond to the project that is currently
selected in MCU workspace tree on the left.
The following table lists the assembler/compiler families of tools that are supported by
Multisim and the MCU Code Manager tabs that are available for configuring those tools:
Assembler/compiler Family
MCU Code Manager tabs
Metalink
- 8051/8052 Cross Assembler
General
Microchip (PIC)
- MPASM absolute and relocatable assembler
- MPLINK linker
- MPLIB librarian
General
C/Assembly
Link
Library
Hi-Tech
- 8051 C Lite compiler
- HLINK linker
- LIBR librarian
General
C/Assembly
Library
Hi-Tech
- PICC Lite compiler
- LINK linker
- LIBR librarian
General
C/Assembly
Library
Documentation for Supported Tools
User documentation for the supported tools is found at the following:
•
•
•
•
Metalink assembler — ...\Program Files\National
Instruments\Circuit Design Suite 10.0\documentation\MetaLink
8051 Cross Assembler Guide.pdf.
Microchip MPASM assembler — ...\Program Files\National
Instruments\Circuit Design Suite 10.0\documentation\DS33014J.pdf.
HI-TECH 8051 C compiler — ...\Program Files\HI-TECH
Software\HC51\9.60\docs\manual.pdf.
HI-TECH PICC Lite compiler — go to www.htsoft.com and download HI-TECH PICC
(V9.50PL2).
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MCU Project Build Settings
3.3.1
8051 Workspace Build Settings Example
In the example shown in “3.1 MCU Code Manager Overview” on page 3-1, project1 is
selected. The Metalink assembler is selected for the project. Since this is an absolute
assembler, the build settings for it are very simple. Consequently, only the General tab is
available to configure the build settings. The Intermediate files and Output files paths are
disabled because the Metalink assembler does not allow you to redirect your output.
After the output machine code file (*.hex) is generated, the contents must be loaded into the
Multisim simulation engine in order to simulate the circuit.
To the set the output *.hex file generated during a build step, select the file from the
Machine code file for simulation drop-down list.
To see the whole path name of output files:
1. Click Show machine code for simulation location on disk. Windows Explorer opens in the
folder where the output file will be located.
In the screen capture below, project2 of 8051workspace is selected in the MCU Code
Manager. Project2 has the “Hi-tech C51-Lite compiler” selected as the tool. This is a C
compiler which compiles and links code in order to produce an output machine code file
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(*.hex), and is more advanced than the Metalink assembler. It has three tabs (General,
C/Assembly, and Library) to configure its build settings.
The assembler or compiler type determines the type of output target files that you can
generate. In the screen capture above, the Hi-Tech C51 Lite compiler is chosen.
Consequently, there are two types of target files that you can create: a machine code file and
a library file. If you choose a library file, the compiler generates object files from the source
files and places them in the specified library file instead of creating a machine code file. The
library file is configured in the Library tab.
There is a C/Assembly tab (see below) in addition to the Library tab available to allow you to
configure the Hi-Tech tools further. One of the advanced features of the Hi-Tech tools is that
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MCU Project Build Settings
intermediate and output files generated by the Hi-Tech C51 Lite can be redirected - therefore
the Intermediate files and Output files paths are enabled in the General tab.
The above shows the MCU Code Manager for MCU U1 in “3.1 MCU Code Manager
Overview” on page 3-1. The C/Assembly tab of the Hi-Tech C51 Lite compiler for
project2 is displayed.
The Project options edit box contains the compiler line options for the C51 Lite compiler. The
default settings are normally sufficient to build an 8051 Hi-Tech C program but you can
customize the options based on the Hi-Tech C51 Lite documentation (see “Documentation for
Supported Tools” on page 3-4).
The Libraries edit box is where you can specify pre-existing libraries to be linked into the
final build. In the above screen capture, one library file will be linked into the final build.
Use the Add library file button to display a file browse window to find the library that should
be linked into the build and automatically add the library file path to the Libraries edit box.
The Library tab, as shown below, is enabled only if the output target selected in the General
tab is a library. The Project options edit box in the Library tab displays the command line
options used when the Hi-Tech tools generate the library. The screen capture below shows
that the Library options are disabled since the output selected for project2 is a hex file.
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Refer to the Hi-Tech compiler documentation for more details on its command line options
(see “Documentation for Supported Tools” on page 3-4).
The above screen capture shows the MCU Code Manager for MCU U1 in “3.1 MCU Code
Manager Overview” on page 3-1. The Library tab of Hi-Tech C51 Lite compiler for
project2 is displayed.
The tabs for the other assembler/compiler files are all similar except that the command line
options in the C/Assembly and Library tabs are different for each tool. Refer to the
assembler/compiler documentation for each tool for more information on the options that can
be used with them (see “Documentation for Supported Tools” on page 3-4).
The tab that was not shown in the above example is the Link tab. The Hi-Tech compilers have
the ability to pass on the command line options to their linker tool from the compiler. This
means that the command line options for both the compiler and the linker can be specified all
at once in the command line options for the compiler, which is when no Link tab is required.
The Microchip relocatable assembler requires the Link tab to configure the command line
options for MPLINK, its linker. The C/Assembly tab for the Microchip tools displays the
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MCU Project Build Settings
options for the compiler, MPASM. The figure below shows an example of the C/Assembly tab
for the Microchip assembler.
Use the Link tab for the Microchip assembler to add any libraries that need to be linked into
the final build and the linker options that have to be passed to MPLINK. The next screen
capture shows an example of the Link tab.
Note The Microchip assembler has both absolute and relocatable assembler. To use
MPASM in relocatable assembler mode, you must add the /o option to the Project
options edit box in the C/Assembly tab shown above, to generate the object files (*.o)
used in the linking stage. Otherwise the object files do not generate and only the
machine code file (*.hex) will be generated as the output file. You must also write
your code in a relocatable fashion using the CODE directive before the code can be
assembled in relocatable mode.
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The Link tab for the Microchip MPLINK tool displays command line options in the
Project options edit box and provides a way of specifying the libraries that should be linked
into the final build.
3.3.2
Loading an External Hex File Project
The build settings described in the previous section are for standard projects that have an
assembler/compiler tool associated with them. The second type of project, (load external file
project) requires no tools. Only the machine code file path must be configured. The
screenshot below shows the General tab for a load external hex file project in the MCU Code
Manager. During simulation, the Machine code file specified in the edit box containing the
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Building an MCU Workspace
opcodes is loaded into the simulation and run. It is also possible to load the code into an
XROM part associated with the MCU as is done for standard projects.
3.4
Building an MCU Workspace
To build an MCU workspace, the proper build settings must be configured in the MCU Code
Manager as described in the previous sections and all necessary source files must be present in
the active MCU project. The assembler/compiler tools selected in the General tab of the MCU
Code Manager for the active project, are invoked during the build to generate the appropriate
files. These files can be machine code files (*.hex), object files, libraries, listing files and
any other intermediate or output files described in the tool’s documentation (see
“Documentation for Supported Tools” on page 3-4).
To build the MCU Workspace:
1. From the MCU menu, navigate to the submenu of the MCU that you wish to build and
select Build.
Or
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Right-click on the workspace or active project item in the Design Toolbox to display the
context menu and select Build.
The results of the build are displayed in the Results tab of the Spreadsheet View. An example
is shown below. If the build is successful, you will have either a *.hex or *.lib file in the
output path where your output files should go. You can verify this by using Windows Explorer
to view the files in that subdirectory.
3.4.1
Errors and Warnings
If there are errors or warnings in your build, they will be displayed in the Results tab.
To find an error:
1. Double-click on the line displaying the error in the Results tab. The file that contains the
error comes into focus with the cursor placed on the line corresponding to the error.
2. In the example below, there are two errors generated by the Metalink assembler listed: line
#5 and line #6. Double-click on either of these lines to open main.asm and place the
cursor on lines 5 and 6 respectively.
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Building an MCU Workspace
3. Correct the errors in the source file and then build the MCU workspace again, continuing
in the same manner until the build is error-free.
3.4.2
Simulation of Machine Code File
Standard Projects
After building the MCU workspace successfully, simulate the circuit containing the MCU
component by selecting Simulate/Run. If you try to run the simulation without building the
MCU workspace first, Multisim prompts you to build the MCU.
When you build the MCU workspace, listing files (*.lst) are generated that are loaded into
Multisim for debugging purposes. Depending on the assembler/compiler tool, the listing files
contain a combination of data such as opcodes, where the opcodes should reside in the MCU
internal ROM, error information, assembly instructions corresponding to the opcodes and the
matching line of source code for each assembly instruction. If the listing file is missing, or
cannot be loaded into Multisim, then no instruction level debugging can be performed on the
MCU.
The intel hex format machine code file (*.hex) that is generated by the build is also loaded
into Multisim at the start of simulation so that the MCU component’s internal ROM
representation can be loaded with the opcodes that should be executed during simulation.
This machine code file path is specified in the General tab of the MCU Code Manager. You
can check that the correct machine code file exists in the machine code file path if Multisim
has trouble loading it.
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Load external hex file projects
Standard MCU projects generate the *.hex file during the build step. However the *.hex
file does not have to be generated for load external hex file projects. The machine code file
specified in the General tab of the MCU Code Manager is loaded at the start of simulation. It is
still possible to debug through disassembled assembly instructions for the MCU during
simulation in the Debug view since the opcodes are disassembled when the *.hex file is
loaded.
Simulating MCU with XROM
The General tab of the MCU Code Manager allows an XROM (external ROM) component to
be used with the MCU. There are three scenarios that can happen relating to XROM:
•
If no XROM is selected, the machine code (*.hex) file opcodes are loaded entirely into
the MCU as described in all of the other examples above for standard and load external
hex file projects.
• If an XROM is selected and the Load machine code (*.hex) file into XROM checkbox is
selected, the machine code file generated by the MCU build is loaded entirely into the
XROM. None of the opcodes are loaded into the MCU; the internal ROM of the MCU
will be empty (filled with no-ops).
• If an XROM is selected and the Load machine code into XROM checkbox is not selected,
the machine code file generated by the MCU build is loaded into the MCU’s internal
ROM, but any opcodes that should be loaded into memory address extending beyond the
physical size of the internal ROM are loaded into the XROM at those very high memory
addresses.
The example below shows a circuit containing an MCU (U1) and an XROM (U2) where the
opcodes in the *.hex file generated during the build step for a standard project project1
is loaded entirely into the XROM (U2). The simulation is paused and the XROM Memory
View shows that the opcodes are indeed loaded into U2 and that there is nothing in U1 as
shown in the MCU Memory View. The bottom right side is a snippet from the MCU Code
Manager settings for project1 that shows the XROM settings. The *.hex file is
generated using the 8051 Metalink assembler from the main.asm source code:
$MOD51
;This includes 8051 definitions for the metalink assembler
MOV ACC,#08H
LOOP:
JMP LOOP
END
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Building an MCU Workspace
The circuit containing MCU U1 and XROM U2 is configured so that during simulation, the
opcodes generated from the source code for project1 are loaded entirely into the XROM
as shown in the XROM Memory View.
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Chapter 4
Multisim MCU Module Source Code Editor
This chapter describes Multisim MCU’s Source Code Editor.
The following are described in this chapter.
4.1
Subject
Page No.
Opening a Source Code File
4-1
Building Source Code Files
4-1
Source Code View
4-2
Opening a Source Code File
To open a source code file in the editor:
1. Double-click on the name of the source code file (for example, main.c or main.asm)
in the Design Toolbox.
2. Optionally, select MCU/Show Line Numbers if you wish to display line numbers in the
source code view.
4.2
Building Source Code Files
Source code files must be built to create a machine code (intel hex) file to load into the MCU
at the start of simulation. Also, any changes in source code files will not take effect until the
MCU project is built.
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To build source code files:
1. Select MCU/<MCU name, e.g., MCU 8051 U1>/Build.
Or
Right-click on the desired source code file in the Design Toolbox and select Build.
The Build command invokes the appropriate compilers, assemblers and linkers, and then
loads the error, listing and hex files that they generate into Multisim. Errors, warnings and
messages display in the Results tab of the Spreadsheet View.
If the build is successful, the hex file is loaded into the appropriate MCU or external ROM. If
it is unsuccessful, the ROM is filled with zeros.
To go to the line of source code associated with an error:
1. Double-click on the error in the Results tab.
4.3
Source Code View
Sections of the Multisim MCU Module’s Source Code Editor are color-coded to denote the
text type:
• Blue text — key words
• Green text — notes
• Black text — all other text, including data, errors.
Note If you type text with an error (spelling, incorrect syntax) into a key word section of the
code, the text changes color from blue to black.
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Source Code View
Notes
Data
Key
words
Error
To save the source code file, select File/Save from the source code view.
To print the source code file, select File/Print from the source code view.
To find a text string in the source code:
1. Select Edit/Find to display the Find dialog box.
2. Enter the desired string and click Find Next.
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Chapter 5
Multisim MCU Module Debugging Features
This chapter describes Multisim MCU’s Debugging Features.
We also recommend that you read the Multisim MCU Module Tutorial chapter of
Getting Started with NI Circuit Design Suite.
The following are described in this chapter.
5.1
Subject
Page No.
Definitions
5-1
Opening a Debug View
5-2
Debug Window Settings
5-3
Simulation Markers
5-4
Breakpoints
5-4
Stepping and Breaking
5-6
Memory View
5-7
Definitions
After a MCU project has been compiled/assembled into a hex file and loaded by the Multisim
MCU Module several different pieces of information are available:
•
•
source code — the original text that was entered by you and passed to the compilers.
listing assembly — the assembly text that is output by the compiler into the listing files.
This form assembly has variable names and other extra notations from the compiler which
is useful when debugging or analyzing the output of a C program. If the original source
code was assembly the listing assembly is often identical; only when macros are used does
it differ.
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•
disassembly — created by the Multisim MCU Module from the raw hex opcodes. This is
often similar to the listing assembly, however, it usually contains absolute values instead
of variable names, except for the jump/goto instructions which use the named labels.
The Multisim MCU Module includes code and debugging windows in addition to Multisim’s
standard circuit windows. Inside the debugging windows a dropdown list allows you to pick
different debugging views. The views show different subsets of the same information, and the
debug window settings let you further filter and customize what the information that is
presented in these views.
5.2
Opening a Debug View
After an MCU's project has been built (without errors) using the Build command the debug
window becomes accessible.
To open the debug window for a particular MCU, select MCU/<MCU name, e.g., MCU 8051
U1>/Debug View.
This opens a new window in Multisim with a drop-down list at the top that you use to select
between the different views.
There is one view available for each source code file, as well as one for the disassembly of the
entire project. By default, when you open a Debug View the project disassembly view which
is a complete disassembly of the ROM for the relevant MCU opens. In the project
disassembly view, every memory address displays from address zero to the maximum address
of the ROM. The project disassembly view always shows the disassembly (not the listing
assembly) because it shows memory addresses which may not have a corresponding listing
(such as the opcodes from statically linked libraries).
To switch to another of the available views, left-click on the drop-down list.
The source file debug listing view is similar to the listing text that a compiler generates when
it builds a single file. It contains a subset of the information available in the complete ROM
disassembly, but the information is sorted into the order of the original source code, rather
than the memory address.
Note The debug file view can also be launched directly — right-click the appropriate file in
the Design Toolbox and select Debug View.
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Debug Window Settings
5.3
Debug Window Settings
To select the information to view in the Debug view:
1. Select MCU/Debug View Format and select the desired option.
Or
Right-click on the Debug view and enable the desired option from the Debug View Format
menu item.
Or
Enable the desired button in the MCU toolbar.
These settings are saved as part of each MCU component, thus if you have two
components they can have different settings, however all the views inside the debugging
window will have the same settings.
MCU toolbar buttons:
Button
Description
Source Code button. Enable to debug through the original source code or
the assembly from the compilers listing files/multisim disassembler. Applies
to the file debugging views, not to the project disassembly.
Disassembly button. Determines whether you see the listing assembly text
or the version from the disassembler. Applies to the file debugging views, not
to the project disassembly.
Show Secondary Language as Comments button. Enables/disables one of
two things. If you are looking at the project disassembly view or if you are
looking at the listing assembly or disassembly of a file it will add the original
source code corresponding to those lines as comments above or beside the
assembly. If you are viewing the source code debug listing then this will
show the corresponding listing assembly/disassembly as comments below
the source code.
Show Line Numbers button. Displays the line numbers in the Debug View.
Show Memory Addresses in Debug View button. Enables/disables the
showing of memory addresses for any text that shows source code in any of
the debug listing views.
Show Memory Addresses in Assembly Code button. Enables/disables the
showing of memory addresses for any text that shows listing assembly or
disassembly in any of the debug listing views.
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Button
Description
Show Hex Opcodes in Assembly Code button. Enables/disables the
showing of the hex values of opcodes for any text that shows listing
assembly or disassembly in any of the debug listing views.
Show Jump/Goto Labels button. Enables/disables the showing of the
jump/goto labels for any text that shows listing assembly or disassembly in
any of the debug listing views.
Show Headings Above Code button. Enables/disables the showing of the
heading comments above each block of source or assembly code which
labels the different fields being shown in the text.
5.4
Simulation Markers
The margin that runs down the left side of the MCU debug windows and Source Code View is
where breakpoints and simulation markers are shown. When you pause the simulation, a
yellow arrow in the bar on the left side of the source code indicates the current line of
execution which corresponds to the current value of the program counter (PC) in that MCU.
Since each line of source code may actually refer to many opcodes, the current program
counter may actually be located somewhere in the middle of the opcodes for a line when you
pause the simulation.
The simulation marker also appears in the debug view, which is where most of the debugging
is done. If your debug view is currently set to show source code, it behaves the same way the
source code window does. If you are viewing the disassembly or the listing assembly, the
indicator is located on the line that contains the memory address that corresponds to the
program counter. Since the debug view corresponds to a single MCU it has a maximum of
one simulation marker. However, the source code view may have more than one indicator if
there are two MCU instances which share that MCU project (this can only happen if you have
MCU components inside subcircuits or hierarchical blocks).
5.5
Breakpoints
You can place breakpoints in either source code or debugging views. Breakpoints can only be
added to lines that correspond to real memory addresses, therefore they cannot be placed on
comments or other lines that do not map to any real opcodes. Before breakpoints can be
placed the project must be built (see “4.2 Building Source Code Files” on page 4-1).
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Breakpoints
To place a breakpoint:
1. Double-click on the margin at the left edge of the source code or debugging window.
Breakpoints are displayed as a red dot in the left margin beside any line of source code or
assembly.
Or
Select the line of source code or debug listing text that the breakpoint should be placed on
and choose the Toggle Breakpoint button in the Simulation toolbar
Or
Right-click on the line of source code or debugging text and choose Toggle Breakpoint
from the context menu.
To remove a breakpoint, repeat any of the above.
A breakpoint placed on a source code window will also be visible in the debug view. These
are simply two different ways of looking at the same information. Breakpoints that are placed
on listing assembly or disassembly views that are associated with a line of source code, even
if they are in the 'middle' of the opcodes for that source code, show up in any source code
views. Breakpoints placed on source code correspond to the first memory address associated
with that line of source code in the disassembly or listing assembly.
After each build the breakpoints may be adjusted based on the changes to the source code and
may shift slightly in both views. This happens because breakpoints placed in the source code
view will remain 'locked' to the line of source code on which they were placed even if changes
result in the compiler moving the memory address of the opcodes that correspond to the
source code. Breakpoints that are placed on the listing assembly or the disassembly remain
'locked' to the exact memory address, so if the source code is modified and then built they
may shift their position in the source code view to the source code that now corresponds to
that memory address.
If MCU components are placed in hierarchical blocks or subcircuits it becomes possible to
have two different 'instances' of the same component in your circuit. In this case both MCU
components share the same MCU project and source code files, and therefore a breakpoint
will be placed in each of MCU components. Toggling the breakpoint on or off in the source
code toggles them all on or off, however toggling them on or off in the debug view only
removes the breakpoint for the corresponding component. The breakpoint marker in the
source code view only disappears when all the breakpoints in all the MCU's debug windows
are removed.
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5.6
Stepping and Breaking
The controls for simulation stepping and breaking into an MCU are located in the Simulation
toolbar, and also in the MCU menu.
When you select the Pause Simulation toolbar button menu item during a simulation, the
simulator stops at the next SPICE timestep, possibly leaving the CPU simulator in midinstruction. If you press the Pause Simulation at Next MCU Instruction Boundary button,
the simulation waits slightly longer before breaking. If the currently activated window and
view is displaying listing assembly or disassembly then the simulation break does not cause
the simulation to stop until it reaches the begining of a new MCU opcode. If the current
window and view is displaying source code then the simulator continues until it reaches the
start of an opcode which is associated with the start of the next line of source code.
The stepping functions are Step into, Step over, Step out and Run to cursor. All of these
buttons work by starting a simulation and then stopping when a certain point is reached. The
behavior depends on whether the view that is active is showing source code (as the primary
language) or listing assembly/disassembly.
If you click the Step into toolbar button, the simulator starts and runs until it reaches the next
line of source code or listing assembly/disassembly. If the current opcode is the start of a
function call, the Step into command follows the call to its new location and breaks at the next
opcode.
If you click the Step over button, the simulator starts and runs until it reaches the next line of
source code or listing assembly/disassembly. If the current opcode is the start of a function
call then Step over does not follow the call, but rather breaks at the first opcode after the
functions return. Another way of thinking of this is that the simulator breaks at the start of the
first opcode where the call stack depth is less than or equal to the current value.
If you click the Step out button, the simulator starts and runs until it reaches the line of source
code or listing assembly/disassembly that immediately follows the return from the current
function. Another way of thinking of this is that the simulator breaks at the start of the first
opcode where the call stack depth is less than the current value.
For a demonstration of these functions, refer to the Multisim MCU Module Tutorial chapter
of Getting Started with NI Circuit Design Suite.
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Memory View
5.7
Memory View
To display an MCU’s memory view, select MCU/<MCU name, e.g., MCU 8051 U1>/Memory
View. A dockable window opens which contains several spreadsheet-like grids of data.
These grids contain data only while the simulation is running and in a paused state. When
paused, they represent a snapshot of the internal registers and memory banks for that
component at a point in simulation time. Different MCU's have different subsets of these
grids depending on the features of that microchip. While the simulation is paused these
values can be used to examine the internal state of the component and also to manually
modify them.
To modify the values, click on the corresponding grid entry and type in new values in the
same format as the previous values.
Note For details on the memory view, refer to “A.1 8051/8052 Microcontroller Units” on
page A-1 and “A.2 PIC16F84/16F84A Microcontroller Units” on page A-3
External RAM and ROM components also have memory views. When the simulation is
paused, the you can view the contents of the memory for these parts. See “A.3 RAM” on
page A-4 and “A.4 ROM” on page A-5 for details.
 National Instruments Corporation
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Appendix A - Multisim MCU Module Parts
This appendix contains information on components that are specific to the Multisim MCU
module.
A.1
8051/8052 Microcontroller Units
The 8051 and 8052 microcontrollers combine a CPU, data memory, program memory, and
built-in external memory on a single chip.
To show/hide the elements of the 805x:
1. Select MCU/<MCU name, e.g., MCU 8051 U1>/Debug View to display the MCU’s debug
view. (You must build the file first).
2. Select MCU/<MCU name, e.g., MCU 8051 U1>/Memory View to display the MCU’s
memory view.
To change the values for the placed 805x:
1. Double-click on the placed MCU to display its properties dialog box and click on the
Value tab.
2. Change the values as desired:
• Built-in External RAM — the external on-chip RAM for the MCU, as displayed in the
XRAM section of the MCU Memory View.
• ROM Size — the ROM for the MCU, as displayed in the IROM section of the MCU
 National Instruments Corporation
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Memory View.
• Clock Speed — the speed of the MCU’s internal clock.
3. Click OK to close the dialog and accept the changes.
MCU Memory View
You can collapse/expand the fields in the MCU Memory View as shown below.
Click to expand
Click to collapse
•
•
•
•
SFR is the MCU’s Special Function Registers.
IRAM is the internal RAM (Random Access Memory) of the MCU. Shows the data that is
inside the MCU's memory and is modified as the program runs. The green shaded area
shows the four “R” register banks; the currently selected one is brighter than the other
three.
IROM is the internal ROM (Read Only Memory) of the MCU. Shows the program
memory code in hexadecimal format. These are the actual machine instructions that the
simulation uses when it is activated. The left column shows the memory address and the
header row shows the offset from the address on the left.
XRAM is the MCU’s external on-chip RAM.
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PIC16F84/16F84A Microcontroller Units
A.2
PIC16F84/16F84A Microcontroller Units
To show/hide the MCU Memory View:
1. Select MCU/<MCU name, e.g., MCU PIC16F84A U1>/Memory View.
To change the speed of the internal clock for a placed PIC16F84/A:
1. Double-click on the placed MCU to display its properties dialog box and click on the
Value tab.
2. Change the value in the Clock Speed field as desired.
3. Click OK to close the dialog and accept the changes.
MCU Memory View
You can collapse/expand the fields in the MCU Memory View as shown below.
Click to expand
Click to collapse
•
Registers contains the SFRs.
 National Instruments Corporation
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Multisim MCU User Guide
•
•
•
•
•
A.3
IRAM contains the internal RAM (Random Access Memory) of the MCU. Shows the data
that is inside the MCU's memory and is modified as the program runs. The colored areas
represent SFRs (Special Function Registers), GPRs (General Purpose Registers) and
different memory banks.
EEPROM (Electrically Erasable Programmable Read Only Memory) contains the data
EEPROM.
IROM is the internal ROM (program memory) of the MCU. Shows the program memory
code in hexadecimal format. These are the actual machine instructions that the simulation
uses when it is activated. The left column shows the memory address and the header row
shows the offset from the address on the left.
Stack contains the processor stack view.
Configuration contains the PIC configuration bits.
RAM
The RAM Family in the MCU Module Group contains a number of RAM devices for use with
the Multisim MCU Module devices.
Click to collapse
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ROM
The RAM Memory View is used to view the contents of the RAM chip while debugging.
To show/hide the RAM Memory View:
1. Select MCU/<RAM name, e.g., RAM HM1-65642-883 U2>/Memory View.
A.4
ROM
The ROM Family in the MCU Module Group contains a number of ROM devices for use with
the Multisim MCU Module devices.
Click to collapse
The ROM Memory View is used to view the contents of the ROM chip while debugging.
To show/hide the ROM Memory View:
1. Select MCU/<ROM name, e.g., ROM 27C128-12L U3>/Memory View.
 National Instruments Corporation
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Multisim MCU User Guide
Appendix B - Support and Services
B.1
Technical Support and Professional
Services
Visit the following sections of the National Instruments web site at ni.com for technical
support and professional services:
•
Support — online technical support resources at ni.com/support include the
following:
• Self-Help Resources — For answers and solutions, visit the award-winning National
Instruments web site for software drivers and updates, a searchable KnowledgeBase,
product manuals, step-by-step troubleshooting wizards, thousands of example
programs, tutorials, application notes, instrument drivers, and so on.
• Free Technical Support — All registered users receive free Basic Service, which
includes access to hundreds of Application Engineers worldwide in the NI Discussion
Forums at ni.com/forums. National Instruments Application Engineers make sure
every question receives an answer. For information about other technical support
options in your area, visit ni.com/services or contact your local office at
ni.com/contact.
• Training and Certification — Visit ni.com/training for self-paced training,
eLearning, virtual classrooms, interactive CDs, and Certification program information.
You also can register for instructor-led, hands-on courses at locations around the world.
• System Integration — If you have time constraints, limited in-house technical resources, or
other project challenges, National Instruments Alliance Partner members can help. To
learn more, call your local NI office or visit ni.com/alliance.
If you searched ni.com and could not find the answers you need, contact your local office or
NI corporate headquarters. Phone numbers for our worldwide offices are listed in the front of
this manual. You can also visit the Worldwide Offices section of ni.com/niglobal to
access the branch office web sites, which provide up-to-date contact information, support
phone numbers, email addresses, and current events.
 National Instruments Corporation
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Multisim MCU User Guide
Index
Numerics
8051 MCU A-1
8052 MCU A-1
B
breaking 5-6
breakpoints 5-4
build errors and warnings 3-12
building MCU projects 4-1
D
debug window settings 5-3
L
loading external hex file project 3-10
M
machine code file simulation 3-13
managing files in MCU workspace 2-4
MCU Code Manager
file management 3-3
MCU Code Manager overview 3-1
MCU design overview 2-1
MCU project build settings 3-3
MCU Wizard 2-3
MCU workspace 3-11
memory view 5-7
O
opening debug view 5-2
S
simulation markers 5-4
source code file 4-1
stepping 5-6
 National Instruments Corporation
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Multisim MCU User Guide
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