embOS for Renesas R8C was developed for and with Renesas's HEW for R8C and supports all memory models offered by this compiler. It comes with an easy to use start project for HEW embedded workbench. Software development with Renesas emulator is supported.

Resources and performance data

Memory usage
Kernel size (ROM)	1281 bytes
Kernel RAM usage	28 bytes
RAM usage per task control block	18 bytes
RAM usage per resource semaphore	4 bytes
RAM usage per counting semaphore	2 bytes
RAM usage per mailbox	12 bytes
RAM usage per software timer	12 bytes
RAM usage event	0 bytes
Min. stack-size per task (RAM)	42 bytes
Timing
Context switching time	437 clock cycles (21.85 µs), independent of number of tasks
Interrupt latency time	TBD
Kernel CPU usage/TICK	less than .4% 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 timings given above were measured with embOS release build on an R8C/1B CPU running at 20MHz in NEAR memory model.

embOSView offers system analysis during runtime

Available Emulators

• Renesas

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Additional information

Renesas Web site for additional compiler and CPU info / support

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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:  Renesas NC30  Version 5.43.0
Assembler: Renesas AS30  Version 5.14.0
Librarian: Renesas LB30  Version 1.02.0
Workbench: Renesas HEW   Version 4

New features

Version 3.32o

NONE.
Initial version for R8C HEW, based on embOS sources 3.32o.

Improvements

Version 3.32o

NONE.
Initial version for R8C HEW, based on embOS sources 3.32o.

Program corrections

Version 3.32o

NONE.
Initial version for R8C HEW, based on embOS sources 3.32o.

Known problems / Limitations

Version 3.32o

NONE

Release history

Version	Release date	Short explanation
V3.32o	22. Nov 2007	Initial version for R8C HEW

Miscellaneous

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