Introduction to uCOS II v2 6 m7

Introduction to uCOS-II V2.6


About SwiftACT
• A Technology services startup company
o

Under establishment

• Areas of specialties:
o
o

Mobile telecommunication services development
Embedded systems development

• Types of services:
o
o
o
o

Consultation
Managed services
Sourcing
Training

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6

About Me
• Graduated 2004
o

ECE, ASU: 5 yrs distinction

• 5+ years in embedded systems development
o

SDLC, Apps, MW, DD, Porting, ...

• 3+ years in SW engineering
o

PSP, CMMI, Systematic reuse, ...

• 3+ years in SW testing
o

IBM certified, ISTQB certified, ...

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Copyright
• Materials in this course is the property of Amr Ali Abdel-Naby.
• Reproduction or transmission of the materials in any manner

without the copyright owner permission is a law violation.

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Course References
• MicroC/OS-II The Real-Time Kernel, 2nd Edition, by Jean J.
Labrosse

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Outline
•
•
•
•
•
•
•
•
•
•

Introduction to µC/OS-II
Kernel Structure

Task Management
Time Management
Semaphore Management
Mutual Exclusion Semaphores
Event Flag Management
Message Mailbox Management
Message Queue Management
Memory Management

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Outline
•
•
•
•
•
•
•
•
•
•

Introduction to µC/OS-II
Kernel Structure
Task Management
Time Management

Semaphore Management
Mutual Exclusion Semaphores
Event Flag Management
Message Mailbox Management
Message Queue Management
Memory Management

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Event Flags
• Used for synchronization of tasks with the occurrence of
multiples of events
• Events are grouped
o

8, 16 or 32 bits per group

• Types of synchronization
o
o

ORed: Any event occurred
ANDed: All events occured

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6

Event Flags cont’d

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Event Flags Management APIs
OSFlagCreate ()
OSFlagDel()
OSFlagPost ()

OSFlagAccept ()
OSFlagPend ()
OSQFlagQuery ()
Task

Task

ISR

Amr Ali Abdel-Naby@2010

OSFlagPost()

OSFlagAccept ()
OSQFlagQuery ()

Introduction to uCOS-II V2.6

ISR


Creating an Event Flag Group,
OSFlagCreate
OS_FLAG_GRP *OSFlagCreate (OS_FLAGS flags, INT8U *err)
•
•

flags: A bit pattern that contains the initial values
err:
o
o
o

•

No error
Called from ISR
No available resources

Return value:
o
o

Non-null for successful creation
Null for failure

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Deleting an Event Flag Group,
OSFlagDel
OS_FLAG_GRP *OSFlagDel (OS_FLAG_GRP *pgrp, INT8U opt,
INT8U *err)
•
•

pgrp: A pointer to the desired event flag group to be deleted
opt: Delete options
o
o

•

Delete always
Delete if no pending tasks

err:
o
o
o
o
o
o

No error
Called from ISR
pgrp is not a flag group.
pgrp is null.
Invalid options
There are tasks pending.

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Deleting an Event Flag Group,
OSFlagDel cont’d
OS_FLAG_GRP *OSFlagDel (OS_FLAG_GRP *pgrp, INT8U opt,
INT8U *err)
•

Return value: Null if successful

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Waiting for Events of an Event Flag
Group, OSFlagPend
OS_FLAGS OSFlagPend (OS_FLAG_GRP *pgrp, OS_FLAGS flags,
INT8U wait_type, INT16U timeout, INT8U *err)
•

•
•
•

pgrp: A pointer to the desired event flag group to pend to
flags: A bit pattern that indicates which flags we will wait for
wait_type: Specifies whether you want ALL bits to be set/cleared or
ANY of the bits to be set/cleared as well as flags consumptions or not
timeout:
o
o

0  wait for ever
!0  wait with specific timeout

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Waiting for Events of an Event Flag
Group, OSFlagPend cont’d
OS_FLAGS OSFlagPend (OS_FLAG_GRP *pgrp, OS_FLAGS flags,
INT8U wait_type, INT16U timeout, INT8U *err)
•

err:
o
o
o

o
o
o

•

No error
Called from ISR
pgrp is not a flag group.
pgrp is null.
Timeout
Improper wait type specified

Return value: Final flag group state

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Setting or Clearing Events in an
Event Flag Group, OSFlagPost
OS_FLAGS OSFlagPost (OS_FLAG_GRP *pgrp, OS_FLAGS flags,
INT8U opt, INT8U *err)
•
•
•
•

pgrp: A pointer to the desired event flag group to post to

flags: A bit pattern that indicates which flags will be changed
opt: Indicates whether flags are set or cleared
err:
o
o
o
o

•

No error
pgrp is not a flag group.
pgrp is null.
Invalid options

Return value: Final flag group state

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Looking for Events of an Event Flag
Group, OSFlagAccept
OS_FLAGS OSFlagAccept (OS_FLAG_GRP *pgrp, OS_FLAGS
flags, INT8U wait_type, INT8U *err)
•
•
•
•

pgrp: A pointer to the desired event flag group to pend to
flags: A bit pattern that indicates which flags we will wait for
wait_type: Specifies whether you want ALL bits to be set/cleared or
ANY of the bits to be set/cleared
err:
o
o
o
o
o

•

No error
pgrp is not a flag group.
Improper wait type specified
pgrp is null.
Flags not available

Return value: Final flag group state

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6


Querying an Event Flag Group,
OSFlagQuery
OS_FLAGS OSFlagQuery (OS_FLAG_GRP *pgrp, INT8U *err)

•
•

pgrp: A pointer to the desired event flag group
err:
o
o
o

•

No error
pgrp is null.
pgrp is not a flag group.

Return value: current value of the flag group

Amr Ali Abdel-Naby@2010

Introduction to uCOS-II V2.6