embOS for SH2A CPUs and HEW compiler

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

embOSView with Renesas SH2A CPU

Available Emulators

Renesas

Additional information

Release Notes embOS SH2A for HEW4
RENESAS Web site for additional CPU info / support