Subversion Repositories neorv32

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// # << NEORV32: neorv32_wdt.c - Watchdog Timer (WDT) HW Driver >>                                 #
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// # BSD 3-Clause License                                                                          #
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// # Copyright (c) 2021, Stephan Nolting. All rights reserved.                                     #
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// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
// #################################################################################################
 
 
/**********************************************************************//**
 * @file neorv32_wdt.c
 * @author Stephan Nolting
 * @brief Watchdog Timer (WDT) HW driver source file.
 *
 * @note These functions should only be used if the WDT unit was synthesized (IO_WDT_EN = true).
 **************************************************************************/
 
#include "neorv32.h"
#include "neorv32_wdt.h"
 
 
/**********************************************************************//**
 * Check if WDT unit was synthesized.
 *
 * @return 0 if WDT was not synthesized, 1 if WDT is available.
 **************************************************************************/
int neorv32_wdt_available(void) {
 
  if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_WDT)) {
    return 1;
  }
  else {
    return 0;
  }
}
 
 
/**********************************************************************//**
 * Enable and configure watchdog timer. The WDT control register bits are listed in #NEORV32_WDT_CT_enum.
 *
 * @param[in] clk_prsc Clock prescaler to selet timeout interval. See #NEORV32_CLOCK_PRSC_enum.
 * @param[in] timeout_mode Trigger system reset on timeout when 1, trigger interrupt on timeout when 0.
 **************************************************************************/
void neorv32_wdt_setup(uint8_t clk_prsc, uint8_t timeout_mode) {
 
  uint32_t prsc = (uint32_t)(clk_prsc & 0x07);
  prsc = prsc << WDT_CT_CLK_SEL0;
 
  uint32_t mode = (uint32_t)(timeout_mode & 0x01);
  mode = mode << WDT_CT_MODE;
 
  uint32_t password = (uint32_t)(WDT_PASSWORD);
  password = password << WDT_CT_PASSWORD_LSB;
 
  uint32_t enable = (uint32_t)(1 << WDT_CT_EN);
 
  WDT_CT = password | enable | mode | prsc;
}
 
 
/**********************************************************************//**
 * Disable watchdog timer.
 **************************************************************************/
void neorv32_wdt_disable(void) {
 
  WDT_CT = ((uint32_t)(WDT_PASSWORD << WDT_CT_PASSWORD_LSB)) | ((uint32_t)(0 << WDT_CT_EN));
}
 
 
/**********************************************************************//**
 * Reset (running) watchdog.
 **************************************************************************/
void neorv32_wdt_reset(void) {
 
  WDT_CT = WDT_CT | ((uint32_t)(WDT_PASSWORD << WDT_CT_PASSWORD_LSB));
}
 
 
/**********************************************************************//**
 * Get cause of last watchdog action.
 *
 * @return Cause of last reset/IRQ (0: undefined, 1: external reset, 2: watchdog timeout, 3: watchdog access error (wrong password)).
 **************************************************************************/
uint8_t neorv32_wdt_get_cause(void) {
 
  uint8_t cause = 0;
  uint32_t ctrl = WDT_CT;
  if (ctrl & (1 << WDT_CT_CAUSE)) { // reset/IRQ casued by watchdog
    if (ctrl & (1 << WDT_CT_PWFAIL)) { // reset/IRQ due to wrong password
      cause = 3;
    }
    else { // reset/IRQ due to timeout
      cause = 2;
    }
  }
  else { // external reset
    cause = 1;
  }
  return cause;
}
 
 
/**********************************************************************//**
 * Force watchdog action (reset/IRQ) via wrong-password access.
 **************************************************************************/
void neorv32_wdt_force(void) {
 
  WDT_CT = 0; // invalid access
}