embOS for SH2A was developed for and with Renesas' HEW compiler.
It comes with a start project for the RENESAS RSK7203 eval kit and supports CPUs with or without floating point unit.

Resources and performance data

Memory usage
Kernel size (ROM)	app. 2.4 Kbytes
Kernel RAM usage	49 bytes
RAM usage per task control block	32 bytes
RAM usage per resource semaphore	16 bytes
RAM usage per counting semaphore	8 bytes
RAM usage per mailbox	24 bytes
RAM usage per software timer	20 bytes
RAM usage event	0 bytes
Min. stack-size per task (RAM)	approx. 70/160 bytes (without/with FPU)
Timing
Context switch time	less than 1.7us
Interrupt latency time	0
Kernel CPU usage/TICK	less than .1% 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 SH2 CPU running at 200 MHz.

embOSView offers system analysis during runtime

Available Emulators

• Renesas

Additional information

RENESAS Web site for additional CPU info / support

Board support packages

embOS comes with lots of ready to go start projects and support packages for various SH2A CPUs and starterboards.

CPU	Eval board
Renesas SH2A7203	Renesas RSKSH2A7203
Renesas SH2A7216	Renesas RSKSH2A7216
Renesas SH2A7264	Renesas RSKSH2A7264
Renesas SH2A7286	Renesas RSKSH2A7286
Renesas SH2A7670	Renesas RSKSH2A7670

 

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Release notes

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

Tool chain used for build

The following tools have been used:

Compiler:  RENESAS shc    V9.01.00.001
Assembler: RENESAS asmsh  V7.01.01.000
Librarian: RENESAS optlnk V9.02.00.000
Workbench: RENESAS HEW    V4.02.00.022

Performance

1. Task switch time
   < 1.2us
2. Interrupt latency for Fast interrupt
   zero

New features

Version 3.80g

1. New embOS sources 3.80g
   The new features, improvements and corrections of embOS version 3.80g are desribed in the embOS generig release notes.
2. FPU Library mode check included.
   It is now impossible to run the wrong library with SH2A FPU project settings.

Version 3.62c

1. New embOS sources 3.62c
   The new features, improvements and corrections of embOS version 3.62c are desribed in the embOS generig release notes.

Version 3.52e

1. NONE, Initial release
   This initial release of embOS SH2A for HEW is based on embOS sources 3.52e.

Improvements

Version 3.80

1. Task switch time and interrupt handling improved
   Optimization of the CPU specific scheduler and the new embOS sources V3.80 drastically reduced the task switch time and interrupt handling time.

Version 3.62c

1. Interrupt handling improved
   The interrupt handler functions OS_CallISR() and OS_CallNestableISR() were optimized to increase execution speed of embOS interrupts.

Program corrections

Version 3.60a

1. Preemptive task switch corrected.
   Preemptive task switch did not work under all circumstances. The status register could have been altered during task switch which might have resulted in malfunction when the preempted task was activated again.
2. embOS libraries with FPU support corrected.
   The floating point registers were not handled correctly during task switch.
   Now, all FPU registers are saved and restored during preemptive task switch.
3. UART interrupt handler for embOSView corrected.
   The break interrupt of the UART was not handled. When a break was detected, the default handler was called which ended in an endless loop.
   Now the break interrupt is handled by embOS. The embOS UART reception error interrupt is called and the break interrupt is cleared.

Known problems / Limitations

NONE

Release history

Version	Release date	Short explanation
V3.80g	14. Nov 2008	New embOS sources V3.80g FPU Library mode check included.
V3.80	14. Nov 2008	New embOS sources V3.80 Task switch time and interrupt handling improved
V3.62c	06. Nov 2008	New embOS sources V3.62c Interrupt handling improved
V3.60a	25. Jan 2008	Corrected version, new embOS sources V3.60a
V3.52e	13. Dec 2007	Initial release, based on embOS V3.52e

Miscellaneous

This document was first released with version 3.52e of the software.
Software released earlier is documented internally.
This information is available at request.