Difference between revisions of "Mutex"

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LDREX and STREX<ref name=M3177>The definitive guide to the CORTEX-M3, Second edition - section 10.6 page 177 (ISBN978-1-85617-963-8</ref>  
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LDREX and STREX<ref name=M3177>The definitive guide to the CORTEX-M3, Second edition - section 10.6 page 177 (ISBN978-1-85617-963-8)</ref>
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=References=
 
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[[Category:Embedded]][[Category:ARM]]
 
[[Category:Embedded]][[Category:ARM]]

Revision as of 09:15, 24 March 2012

A Mutex (Mutual Exclusion) is a method used to gain exclusive rights to use a shared resource in programming. Often used when designing software in embedded systems using interrupts and/or RTOS.

Example

In a interrupt driven embedded system there are two devices connected to a CAN bus. Two independent software routines communicate independent of each other with Device A and Device B through a shared CAN bus. See drawing below.

Two software routines fighting for exclusive access to the shared CAN bus

ARM Thumb

LDREX and STREX[1]

References

  1. The definitive guide to the CORTEX-M3, Second edition - section 10.6 page 177 (ISBN978-1-85617-963-8)