embOS for ARM7 / ARM9 / XScale was developed for and with KEIL MDK, compiler RVCT3.0 and supports all memory models offered by this compiler. It comes with easy to use start projects for the KEIL uVision. Initilization code for various ARM CPUs is included. Software development with uVision simulator or debugger with JTAG tools like J-Link ARM ATMEL SAM-ICE or ULINK is possible.

Resources and performance data

Memory usage
Kernel size (ROM)	approx. 3000 bytes
Kernel RAM usage	51 bytes
RAM usage per task control block	32 bytes
RAM usage per resource semaphore	8 bytes
RAM usage per counting semaphore	2 bytes
RAM usage per mailbox	20 bytes
RAM usage per software timer	20 bytes
RAM usage event	0 bytes
Min. stack-size per task (RAM)	56 bytes
Timing
Context switch time	max. 8 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.

embOSView offers system analysis during runtime

Available Emulators

• J-Link ARM
• ARM
• KEIL ULINK

Board support packages

embOS comes with lots of ready to go start projects and support packages for various ARM7/9 CPUs and starterboards.

CPU	Eval board
Atmel AT91M55800	Atmel AT91EB55
Atmel AT91SAM7A3	Atmel AT91SAM7A3-EK
Atmel AT91SAM7S256	Atmel AT91SAM7S256-EK
Atmel AT91SAM7S64	Atmel AT91SAM7S64-EK
NXP LPC2468	Embedded Artists LPC2468-16
NXP MCB2100	Keil MCB2100
NXP MCB2300	Keil MCB2300
ST STR710	ST STR710

 

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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:  ARM/Thumb C/C++ Compiler armcc,   RVCT3.1 [Build 934] for uVision
        Assembler: ARM/Thumb Macro Assembler armasm, RVCT3.1 [Build 934] for uVision
        Librarian: ARM Archiver armar,               RVCT3.1 [Build 934] for uVision
        Workbench: KEIL uVision3 Version 3.34
      

New features

Version 3.60d1

1. LPC2378 supported
   embOS for KEIL MDK now comes with a board support package for the NXP LPC 2378 device.
   It runs on an KEIL MCB2300 eval board, but may be used with other hardware as well.

Version 3.60d

1. LPC2468 supported
   embOS for KEIL MDK now comes with a board support package for the NXP LPC2468 device.
   It runs on an embedded Artists eval board, but may be used with other hardware as well.
2. New embOS sources version 3.60d
   embOS version 3.60d offers several new features which are described in the embOS generic manual.

Version 3.52a

1. AT91M55800 supported
   embOS for KEIL MDK now comes with a board support package for the ATMEL AT91EB55 eval board which may also be used for other target boards with the AT91M55800 CPU.
   Debugging in RAM, Flash and simulator is supported.

Version 3.32f

All features of generic 3.32f kernel supported.

Improvements

Version 3.60d1

1. RAM.ini files for RAM targets improved
   The debugger does not automatically set the CPU into its initial reset state after downloading an application into the target.
   The new RAM.ini files disables IRQ and FIQ and switches the CPU into supervisor mode after download.
   Without this improvement, the RAM target might run into uninitialized interrupt handlers if an application in Flash or RAM was activated before the debug session and peripherial interrupts were enabled.

Version 3.52c

1. embOS interrupt handler source file RTOSVECT.s eliminated.
   Because the embOS primary interrupt handler is generic for all ARM cores and not target CPU specific, there was no need to place the interrupt handler function into a separate source file.
   The embOS interrupt handler is now included in the embOS libraries. The start projects are therfore simplified and the embOS interrupt handler is always included in the project.

Program corrections

Version 3.52c

1. Task switch from interrupt corrected.
   The previous version failed when a preemptive task switch from interrupt should be performed.
   The debug libraries called the error handler OS_Error() with error code 0xff, the release version might have crashed, if another interrupt occured during the task switch.
   The problem existed in Version 3.52a only and is fixed with version 3.52c.

Known problems/limitations

Version 3.60d

None.

Release history

Version	Release date	Short explanation
V3.60d1	24. Jul 2008	LPC2378 supported
V3.60d	01. Jul 2008	New embOS sources V3.60d
V3.52c	26. Oct 2007	Corrected version.
V3.52a	28. Sep 2007	Update to embOS version 3.52a. AT91M55800 supported.
V3.32f	18. Dec 2006	First version with release history

Miscellaneous

This document was first released with version 3.32f of the software.
Software released earlier is documented internally. This information is available at request.