EMBEDDED SYSTEM SOFTWARE AND RTOS BASICS DIAGRAMS Embedded Systems Software Training Center EMBEDDED SYSTEM SOFTWARE AND RTOS BASICS DIAGRAMS

Diversity of the Embedded Systems The range of embedded systems is extremely diverse both in terms of its scale and nature. There is currently no effective way of classifying the various systems. Embedded device total cost * It is also necessary to add in a time-to-market factor. ！Today development costs have become a significant factor in mass-production. Controls rice cookers to nuclear power plants

Case Example: Embedded system used in car Provided by Toyota Motor Corporation

Software embedded in an equipment and in LSI DSP – Digital Signal Processor LSI – Large Scale Integration

Embedded software size and deployment Sales of embedded s/w is congruous with sales of large s/w systems, like MS Windows

The size of the respondents (the number of employees) Compare this data with your company.

The size of the respondents (sales) Compare this data with your company.

Breakdown of the total development cost in the operating department The cost of software development accounts for 40% of total development costs.

Types of targeted processors The 32 bits era

Programming languages Mainstream is C language

Targeted OS ITRON has the largest sector

Processing Order: Cooperative vs. Preemptive Cooperative Multitasking Preemptive Multitasking Process A OS Process A (low priority, cyclic) Process B1 Process B2 Process B (low priority) Process C Process C (high priority, cyclic) Process D Process D (high priority) Processes (tasks) are run in an infinite loop If task takes too much time (B), need to divide it No overhead occurs Scheduling is performed by the OS Long task is suspended if needed Overhead: caused by OS internals Copyright © 2011 DSR Corporation 12

References Embedded systems: Scheduling: Synchronization Christof Ebert, Jurgen Salecker, “Embedded Software-Technologies and Trends” Steve Heath, “Embedded Systems Design - 2ed” Michael Barr; Anthony J. Massa, “Programming embedded systems: with C and GNU development tools” Scheduling: http://faculty.cs.tamu.edu/bettati/Courses/663/Fall-2001/Slides/sched_approaches.pdf http://faculty.cs.tamu.edu/bettati/Courses/663/Fall-2001/Slides/clock_driven.pdf http://faculty.cs.tamu.edu/bettati/Courses/663/Fall-2001/Slides/priority_driven.pdf Synchronization http://www.isi.edu/~faber/cs402/notes/lecture6.html http://www.isi.edu/~faber/cs402/notes/lecture7.html On-line library http://www.slac.stanford.edu/comp/unix/package/rtems/doc/rtems/index.html QNX architecture http://filene.ru/second Copyright © 2011 DSR Corporation 13 13