Engineering Clinic

Process Sequential Execution of Instructions Tasks Each task is independent since it is controlled by a scheduler or kernel of an Operating System No task can call other tasks. since the Scheduler schedules the tasks Each task is associated with an ID. Each task has priority. for a 1 byte priority assignment, values 0 to 255 is used. higher the value higher the priority Each task should coded in such a way that, they are waiting for a endless - event waiting loop. Each task has a Task Control Block (TCB) Each task will be having its own context and values at an instant. it is having its own Program counter(PC) and stack pointer (SP. Each task will be in any one of the following 4 states idle - After the completion of one cycle of execution, a task will be in idle state until an event is fired ready - the task is ready to execute on the CPU, but the CPU is busy with executing higher priority tasks Running - currently the task is executing on the CPU - only one task can be in this state ...

There are five types of software maintenance Preventive Maintenance - A system may be checked and maintained periodically Corrective Maintenance - Correct the deviation noticed under certain conditions of field use of the system Perfection or Enhancement Maintenance - development team delivers a system on schedule and then finds another design capable of working more accurately and effectively Adaptive Maintenance - Adapt the software to new conditions System Reengineering - previously developed system is reengineered.

People People Senior Manager 1. Responsible for creating environment, 2. Organising, coordinating and managing all communications Project Technical Manager or Team Leader 1. Selecting the language and tools 2. reorganize available software specification 3. Maintain activity graph for starting 4. motivates and encourage implementors Implementors 1. Implements the software and hardware development process 2. uses modeling, source code engineering, testing Customer or End User 1. Specifies the product and its quality requirements Product Embedded System product Process 1. Product Development partitioned into smaller components and modules so that activities defined in the graph for activity are finished Project 1. Design 2. Planning 3. Implementing and testing 4. Debugging and Maintaining

#include reg51.h> void main() { TMOD = 0x20; TH1=-3; SCON = 0x50; TR1 = 1; while(1) { SBUF = 'ABCD'; while(TI=1) { TI=0; } } }

Delay Calculation Crystal frequency = 11.059MHz. 1 machine cycle = 1 / (11.059/12) = 1.085μ s For 1second delay1.085μ s * 921660 = 1 sec (approx) #include reg51.h> main() { int i,j; P0=0xff; for(i=0;i { for(j=0;j } P0=0x00; for(i=0;i { for(j=0;j } }