Algorithm Scheduling
REAL TIME AND EMBEDDED SYSTEMS [ECWM611]
Coursework 1: Report
Submitted by: Louis Thompson
TASK 1
(A)
An embedded system contains the following independent software tasks:
Control: The system performs closed-loop control of a robot. Loop processing takes 10 milliseconds. Alarm monitoring: A set of 5 alarm sensors are connected to the processor via a slow speed serial link. Each individual monitoring transaction (per alarm point) takes 10 milliseconds. It is assumed that all points are scanned in sequence.
Display driving: A standard monitor is used to display system status to an operator. The display subsystem has a dedicated graphics board. It takes a maximum of 20 milliseconds to update the display information.
System identification: A processing algorithm used to mathematically model the robot system. This takes 100 milliseconds to execute.
Organize the execution schedule of these tasks using simple scheduling (FIFO). Use timing diagram to show your solution.
(A) Solution Through the execution order used by the scheduling algorithm the TT (turnaround time; time taken for each process to complete) can be optimized, in that processing tasks with a smaller execution time first leads to better overall TT. In the case above we have display driving aided by the use of a dedicated Graphics card therefore the execution/ TT for this process should increase (n+1) fold where n represents the number of I/O devices being used in this case 1 therefore TT for this process is increased 2fold i.e. (display driving should take 10ms). Based on this info scheduling is done as follows: PROCESS | EXECUTION TIME | P1: CONTROL | 10ms | P2: DISPLAY | 10ms [as there is dedicated GPU] | P3: ALARM MONITORING CONTROL | 50ms | P4: SYSTEM
Coursework 1: Report
Submitted by: Louis Thompson
TASK 1
(A)
An embedded system contains the following independent software tasks:
Control: The system performs closed-loop control of a robot. Loop processing takes 10 milliseconds. Alarm monitoring: A set of 5 alarm sensors are connected to the processor via a slow speed serial link. Each individual monitoring transaction (per alarm point) takes 10 milliseconds. It is assumed that all points are scanned in sequence.
Display driving: A standard monitor is used to display system status to an operator. The display subsystem has a dedicated graphics board. It takes a maximum of 20 milliseconds to update the display information.
System identification: A processing algorithm used to mathematically model the robot system. This takes 100 milliseconds to execute.
Organize the execution schedule of these tasks using simple scheduling (FIFO). Use timing diagram to show your solution.
(A) Solution Through the execution order used by the scheduling algorithm the TT (turnaround time; time taken for each process to complete) can be optimized, in that processing tasks with a smaller execution time first leads to better overall TT. In the case above we have display driving aided by the use of a dedicated Graphics card therefore the execution/ TT for this process should increase (n+1) fold where n represents the number of I/O devices being used in this case 1 therefore TT for this process is increased 2fold i.e. (display driving should take 10ms). Based on this info scheduling is done as follows: PROCESS | EXECUTION TIME | P1: CONTROL | 10ms | P2: DISPLAY | 10ms [as there is dedicated GPU] | P3: ALARM MONITORING CONTROL | 50ms | P4: SYSTEM