watchdog_h8300h.cxx

eCos操作系统源码

//==========================================================================
//
//      devs/watchdog/h8300/h83000/watchdog_h8300.cxx
//
//      Watchdog implementation for Hitachi H8/300H CPUs
//
//==========================================================================
//####ECOSGPLCOPYRIGHTBEGIN####
// -------------------------------------------
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// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.
//
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//####ECOSGPLCOPYRIGHTEND####
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    yoshinori sato
// Contributors: yoshinori sato
// Date:         2002-04-29
// Purpose:      Watchdog class implementation
// Description:  Contains an implementation of the Watchdog class for use
//               with the Hitachi H8/300H watchdog timer.
//
//####DESCRIPTIONEND####
//
//==========================================================================

#include <pkgconf/system.h>             // system configuration file
#include <pkgconf/watchdog.h>           // configuration for this package

#include <cyg/infra/cyg_trac.h>         // tracing macros

#include <cyg/hal/hal_io.h>             // IO register access
#include <cyg/hal/mod_regs_wdt.h>       // watchdog register definitions

#include <cyg/io/watchdog.hxx>          // watchdog API

// -------------------------------------------------------------------------
// Constructor

void
Cyg_Watchdog::init_hw(void)
{
    CYG_REPORT_FUNCTION();
    
    // No hardware init needed.

    resolution          = CYGARC_WDT_PERIOD;

    CYG_REPORT_RETURN();
}

// -------------------------------------------------------------------------
// Start the watchdog running.

void
Cyg_Watchdog::start()
{
    CYG_REPORT_FUNCTION();

    //Stop WDT
    HAL_WRITE_UINT16(CYGARC_TCSR,CYGARC_TCSR_MAGIC);
    //Clear WDT Count
    HAL_WRITE_UINT16(CYGARC_TCSR,CYGARC_TCNT_MAGIC);
    //Start WDT
    HAL_WRITE_UINT16(CYGARC_TCSR,CYGARC_TCSR_MAGIC|
                                 CYGARC_WDT_WT|CYGARC_WDT_TME|CYGARC_WDT_CKS);
    
    CYG_REPORT_RETURN();
}

// -------------------------------------------------------------------------
// Reset watchdog timer. This needs to be called regularly to prevent
// the watchdog firing.

void
Cyg_Watchdog::reset()
{    
    CYG_REPORT_FUNCTION();

    HAL_WRITE_UINT16(CYGARC_TCSR,CYGARC_TCNT_MAGIC);
    
    CYG_REPORT_RETURN();
}

// -------------------------------------------------------------------------
// EOF watchdog_h8300.cxx