PwrLimr_MDD

Module Design Document

For

PwrLimr

Nov 09, 2016

Prepared For:

Software Engineering

Nexteer Automotive,

Saginaw, MI, USA

Prepared By:

Nick Saxton,

Nexteer Automotive,

Saginaw, MI, USA
Change History

Table of Contents1 PwrLimr High-Level Description 4

2 Design details of software module 5

2.1 Graphical representation of PwrLimr 5

2.2 Data Flow Diagram 5

2.2.1 Component level DFD 5

2.2.2 Function level DFD 5

3 Constant Data Dictionary 6

3.1 Program (fixed) Constants 6

3.1.1 Embedded Constants 6

4 Software Component Implementation 7

4.1 Sub-Module Functions 7

4.1.1 Init: PwrLimrInit1 7

4.1.1.1 Design Rationale 7

4.1.1.2 Module Outputs 7

4.1.2 Per: PwrLimrPer1 7

4.1.2.1 Design Rationale 7

4.1.2.2 Store Module Inputs to Local copies 7

4.1.2.3 (Processing of function)……… 7

4.1.2.4 Store Local copy of outputs into Module Outputs 7

4.1.3 Per: PwrLimrPer2 7

4.1.3.1 Design Rationale 7

4.1.3.2 Store Module Inputs to Local copies 7

4.1.3.3 (Processing of function)……… 7

4.1.3.4 Store Local copy of outputs into Module Outputs 7

4.2 Server Runables 8

4.3 Interrupt Functions 8

4.4 Module Internal (Local) Functions 8

5 Known Limitations with Design 9

6 UNIT TEST CONSIDERATION 10

Appendix A Abbreviations and Acronyms 11

Appendix B Glossary 12

Appendix C References 13

PwrLimr High-Level Description

Refer FDD

Design details of software module

Graphical representation of PwrLimr

Data Flow Diagram

Component level DFD

Function level DFD

Constant Data Dictionary

Program (fixed) Constants

Embedded Constants

Local Constants

• For other constants, refer DataDict.m

Software Component Implementation

Sub-Module Functions

Init: PwrLimrInit1

Design Rationale

Init function is present in DataDict.m file but not shown in FDD model. Per the note in SF019B_PwrLimr/PwrLimr in the model, the init function is responsible for updating the low pass filters used in the periodic functions. Additionally, the init function starts up a timer used in the ‘Asst_Lmt_Condition_Determination’ block in the model.

Module Outputs

Refer FDD

Per: PwrLimrPer1

Design Rationale

Refer FDD

Store Module Inputs to Local copies

Refer FDD

(Processing of function)………

Refer FDD

Store Local copy of outputs into Module Outputs

Refer FDD

Per: PwrLimrPer2

Design Rationale

GetTiSpan100MicroSec32bit returns elapsed time in counts where one count is equal to 100 microseconds. Therefore, the value returned from that function is divided by 10 to get the elapsed time in milliseconds.

Store Module Inputs to Local copies

Refer FDD

(Processing of function)………

Refer FDD

Store Local copy of outputs into Module Outputs

Refer FDD

Server Runables

None

Interrupt Functions

None

Module Internal (Local) Functions

None

Known Limitations with Design

None

UNIT TEST CONSIDERATION

None

Abbreviations and Acronyms

Glossary

Note: Terms and definitions from the source “Nexteer Automotive” take precedence over all other definitions of the same term. Terms and definitions from the source “Nexteer Automotive” are formulated from multiple sources, including the following:

• ISO 9000

• ISO/IEC 12207

• ISO/IEC 15504

• Automotive SPICE® Process Reference Model (PRM)

• Automotive SPICE® Process Assessment Model (PAM)

• ISO/IEC 15288

• ISO 26262

• IEEE Standards

• SWEBOK

• PMBOK

• Existing Nexteer Automotive documentation

References