HI7700/4 Real-time OS for SuperH Family

Functions

[Kernel]
The HI7700/4 kernel consists of the following modules. Each module is provided by functions (service calls) .

• Scheduler
  Manages execution sequence of multiple tasks based on their priority levels.
• Task management
  Manages task status such as RUNNING, READY, WAITING or SUSPENDED.
• Task-dependent synchronization
  Changes task status from other task, and synchronizes tasks.
• Interrupt processing
  Returns from an interrupt handler.
• Time management
  Sets system timer used by HI7700/4 kernel and starts user-defined alarm handler, cyclic handler and overrun handler.
• System State Management
  Reports information such as version number of HI7700/4 kernel.
• Synchronization/communication
  Carries out synchronization and communication between tasks. The following function modules are available:
  • Event flag
    Tasks are synchronized by the status of flags managed by the kernel.
  • Semaphore
    Tasks are synchronized by the semaphore counter value managed by the kernel.
  • Mail box
    Tasks are synchronized by sending or receiving a message.
  • Data queue
    Tasks are synchronized by communicating 4-byte data.
• Extended Synchronization/Communication
  Carries out synchronization and communication between tasks. The following function modules are available:
  • Message buffer
    Makes use of variable-length data communication to synchronize tasks.
  • Mutex
    Makes use of priority ceiling protocol for avoiding priority inversion to synchronize tasks.
    
• Memory pool management
  Dynamically allocates/frees memory area used by tasks. Enables efficient use of memory.
• Task exception
  Controls execution of task exceptions by, for example, defining or activating a task exception.
• Cyclic handler function
  Controls the execution of a handler activated periodically.
• Alarm handler function
  Controls the execution of a handler activated at the specified relative-time.
• Overrun handler function
  Con trolls the execution of a handler activated when the specified time has been exceeded.
• Extended service call function
  Renesas original functions are following:
  • Task event flags
    Makes use of task event flag state to synchronize tasks.
  • Cache support function
    Initialize cache, clear cache, and flush cache etc.