embOS for PIC18 was developed for and with Microchips's compiler version 3.32 and supports all memory models offered by this compiler. It comes with easy to use start projects for Microchips's MPLA workbench.

Resources and performance data

Memory usage
RAM usage per task control block	21 bytes
RAM usage per resource semaphore	7 bytes
RAM usage per counting semaphore	4 bytes
RAM usage per mailbox	11 bytes
RAM usage per software timer	10 bytes
RAM usage event	10 bytes
Min. stack-size per task (RAM)	90 bytes
Timing
Context switch time	27.4 µs, independent of number of tasks
Interrupt latency time	zero
Kernel CPU usage/TICK	less than .2% of total calculation time at 1000 Interrupts/second (1ms TICK)
Basic time unit (TICK)	typ. 1 ms, min. 20 µs (50 kHz interrupt frequency)
Features
Max. no. of tasks	Unlimited (by available RAM only)
Max. no. of mailboxes	unlimited (by available RAM only)
Max. no. of semaphores (resource/binary/counting)	unlimited (by available RAM only)
Max. no. of software timers	unlimited (by available RAM only)
Max. no. of priorities	255
Stack size idle task (RAM)	0(no memory needed)
Nested interrupts	permitted
Task switches from within ISR	possible

Absolute values given above were measured with embOS release build on an PIC18 CPU running at 10MHz.

embOSView offers system analysis during runtime

Available Emulators

• Microchip MPLAB ICD2
  

Board support packages

embOS comes with lots of ready to go start projects and support packages for various PIC18 CPUs and starterboards.

CPU	Eval board
Microchip PIC18F87J11	Microchip Explorer 2 - PIC18
Microchip PIC18F8722	Microchip Explorer 2 - PIC18

 

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Release notes

1. Tool chain used for build
2. New features
3. Improvements
4. Program corrections
5. Known problems/limitations
6. Release history
7. Miscellaneous

Tool chain used for build

The following tools have been used:

Compiler:  Microchip MCC18      V3.36
Assembler: Microchip MPASMWIN   V5.37
Librarian: Microchip MPLIB      V4.37
Workbench: Microchip MPLAB IDE  V8.56

New features

Version 3.82o

1. Update to latest embOS generic sources V3.82o.

Version 3.82n

1. Update to latest embOS generic sources V3.82n.

Version 3.82k

1. Update to latest embOS generic sources V3.82k.
2. BSP for PIC18F8722 added.
   embOS comes now with a BSP for PIC18F8722 cpu.

Version 3.80i

First version. None.

Improvements

Version 3.82k

1. The embOS libraries are not longer restricted to PIC18F87J11 cpu only.

Version 3.80i

First version. None.

Program corrections

Version 3.82o

1. Task switch from interrupt corrected.

Version 3.82n

1. Queue implementation corrected.

Version 3.80i

None.

Known problems/limitations

Version 3.80i

None.

Release history

Version	Release date	Short explanation
V3.82o	10. Jan 2010	Update to latest embOS generic sources V3.82o. Task switch from interrupt corrected.
V3.82n	14. Dec 2010	Update to latest embOS generic sources V3.82n. Queue implementation corrected.
V3.82k	22. October 2010	Update to latest embOS generic sources V3.82k. BSP for PIC18F8722 added. embOS library PIC18F87J11 cpu restriction removed.
V3.80i	13. August 2009	First version with release history

Miscellaneous

This document was first released with version 3.80i of the software.
Software released earlier is documented internally. This information is available at request.