hplflash.nc

传感器网络中的嵌入式操作系统源代码

// $Id: HPLFlash.nc,v 1.1.4.4 2003/08/26 09:08:16 cssharp Exp $

/*									tab:4
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 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
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 * Copyright (c) 2002-2003 Intel Corporation
 * All rights reserved.
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/*
 *
 * Authors:		Jason Hill, David Gay, Philip Levis
 * Date last modified:  6/25/02
 *
 */

/**
 * Low level hardware access to the onboard EEPROM (well, Flash actually)
 * @author Jason Hill
 * @author David Gay
 * @author Philip Levis
 */

module HPLFlash {
  provides {
    interface StdControl as FlashControl;
    interface BitSPI as FlashBitSPI;
  }
}
implementation
{
  // SPI mode 0 (clock low at select time)

  // We don't touch select here, it's handled by SlavePinC

  command result_t FlashControl.init() {
    TOSH_CLR_FLASH_CLK_PIN();
    TOSH_MAKE_FLASH_CLK_OUTPUT();
    TOSH_SET_FLASH_OUT_PIN();
    TOSH_MAKE_FLASH_OUT_OUTPUT();
    TOSH_CLR_FLASH_IN_PIN();
    TOSH_MAKE_FLASH_IN_INPUT();

    return SUCCESS;
  }

  command result_t FlashControl.start() {
    /* We do nothing. The 1-wire pin may be low already, so it's too late
       to clear the clock. */
    return SUCCESS;
  }

  command result_t FlashControl.stop() {
    // We ensure flash clock is low (SPI mode 0) */
    TOSH_CLR_FLASH_CLK_PIN();
    return SUCCESS;
  }
  
  command bool FlashBitSPI.txBit(bool bit) {
    if (bit)
      TOSH_SET_FLASH_OUT_PIN();
    else
      TOSH_CLR_FLASH_OUT_PIN();

    TOSH_SET_FLASH_CLK_PIN();

    if (TOSH_READ_FLASH_IN_PIN())
      {
	TOSH_CLR_FLASH_CLK_PIN();
	return TRUE;
      }
    else
      {
	TOSH_wait();
	TOSH_CLR_FLASH_CLK_PIN();
	return FALSE;
      }
  }
}