ds1620.c

这是单板上DPRAM的驱动程序

#include <psos.h>
#include "board.h"
#include "sdev.h"
#include "ds1620.h"

#define DS1620_READ_TEMPERATURE 0xAA
#define DS1620_READ_COUNTER     0xA0
#define DS1620_READ_SLOPE       0xA9
#define DS1620_START_CONVERT_T  0xEE
#define DS1620_STOP_CONVERT_T   0x22
#define DS1620_WRITE_TH         0x01
#define DS1620_WRITE_TL         0x02
#define DS1620_READ_TH          0xA1
#define DS1620_READ_TL          0xA2
#define DS1620_WRITE_CONFIG     0x0C
#define DS1620_READ_CONFIG      0xAC

#define DS1620_DELAY_COUNT      0x50
#define DS1620_CONFIG           0x08

static void   delay1620(void);
static USHORT read1620(Ds1620CfgStruct *pCfg,UCHAR byBits);
static void   write1620(Ds1620CfgStruct *pCfg,USHORT wCode, UCHAR byBits);
static void   access1620(Ds1620CfgStruct *pCfg,UCHAR byInstuction, 
                    USHORT wPara, USHORT *wRtnValue);

#define Ds1620Dat_Tmp(tmp) (((tmp)<0x100)?((tmp)/2):(((tmp)&0xff-0x100)/2))
#define Ds1620Tmp_Dat(tmp) (((tmp)>0)?(((USHORT)((tmp)*2))&0xff):(0x1ff-(((USHORT)(-(tmp)*2))&0xff))); 

static void Ds1620Init(void *pDataBuf, Ds1620CfgStruct *cfg )
{
    USHORT temp_ushort;
    Ds1620CfgStruct*   pCfg =(Ds1620CfgStruct *)(pDataBuf);

/*-------------------------<< Initial data >>-------------------------------*/
    memmove(pCfg,cfg,sizeof(*cfg));
    SetLLDat(&pCfg->Clk,1);     /* 上电时序配置，保证1620处于stand-alone模式 */
    delay1620();
    SetLLDat(&pCfg->Clk,0);    

    access1620(pCfg,DS1620_READ_CONFIG, 0, &temp_ushort);
    if ((temp_ushort & 0x3 )!=( DS1620_CONFIG&0x3))
        access1620(pCfg,DS1620_WRITE_CONFIG, DS1620_CONFIG, NULL); 

    access1620(pCfg,DS1620_START_CONVERT_T, 0, NULL);
}

static int Ds1620Read(void *pDataBuf,void *pBuf, int MaxLen)
{   
    USHORT temp_ushort;
    Ds1620CfgStruct *pCfg;
    if(MaxLen < sizeof(int))return SDE_INVALID_ARG;
    pCfg=(Ds1620CfgStruct *)pDataBuf;
    access1620(pCfg,DS1620_READ_TEMPERATURE, 0, &temp_ushort);
    /* 读到的温度值是实际温度的2倍 */
    *(int *)pBuf=Ds1620Dat_Tmp(temp_ushort);
    return SDE_OK;
}

static int Ds1620Cntrl(void *pDataBuf, int cmd, void *pParam, int maxlen)
{
    int ret;
    USHORT temp_ushort;
    /* PDA *pda= (PDA *)(GetIMMR() & IO_MAP_MASK);  */
    Ds1620CfgStruct*  pCfg =(Ds1620CfgStruct *)(pDataBuf);
    switch(cmd)
    {
        case SDC_REINIT:
            Ds1620Init(pDataBuf,pCfg);
            break;
        /* case SDC_READ_TEMP_HI: */
        case SDC_GET_UPPER_LIMIT:
            if(maxlen!=sizeof(int))return SDE_INVALID_ARG;
            access1620(pCfg,DS1620_READ_TH, 0, &temp_ushort);
            *(int *)pParam=Ds1620Dat_Tmp(temp_ushort);
            break;
        /* case SDC_READ_TEMP_LO: */
        case SDC_GET_LOWER_LIMIT:
            if(maxlen!=sizeof(int))return SDE_INVALID_ARG;
            access1620(pCfg,DS1620_READ_TL, 0, &temp_ushort);
            *(int *)pParam=Ds1620Dat_Tmp(temp_ushort);
            break;
        /* case SDC_WRITE_TEMP_HI: */
        case SDC_SET_UPPER_LIMIT:
            if(maxlen!=sizeof(int))return SDE_INVALID_ARG;
            access1620(pCfg,DS1620_READ_TH, 0, &temp_ushort);
            if(*(int *)pParam!=Ds1620Dat_Tmp(temp_ushort))
            {
            	temp_ushort=Ds1620Tmp_Dat(*(int*)pParam);
                access1620(pCfg,DS1620_WRITE_TH, temp_ushort, NULL); 
            }
            break;
        /* case SDC_WRITE_TEMP_LO: */
        case SDC_SET_LOWER_LIMIT:
            if(maxlen!=sizeof(int))return SDE_INVALID_ARG;
            access1620(pCfg,DS1620_READ_TL, 0, &temp_ushort);
            if(*(int *)pParam!=Ds1620Dat_Tmp(temp_ushort))
            {
            	temp_ushort=Ds1620Tmp_Dat(*(int*)pParam);
                access1620(pCfg,DS1620_WRITE_TL, temp_ushort, NULL); 
            }
            break;
        case SDC_START_CONVERT:
            access1620(pCfg,DS1620_START_CONVERT_T, 0, 0);
            break;
        case SDC_STOP_CONVERT:
            access1620(pCfg,DS1620_STOP_CONVERT_T, 0, 0);
            break;
        case SDC_WRITE_CONFIG:
            access1620(pCfg,DS1620_WRITE_CONFIG, *(int*)pParam, NULL); 
            break;
        case SDC_READ_CONFIG:
            if(maxlen!=sizeof(int))return SDE_INVALID_ARG;
                access1620(pCfg,DS1620_READ_CONFIG, 0, &temp_ushort);
            *(USHORT *)pParam=temp_ushort;
            break;
        default: 
            return SDE_UNKNOW_CMD;

    }/* end of switch(cmd) */
    return SDE_OK;
}

char *Ds1620BspInit(int DEV, char *FreeMemPtr, Ds1620CfgStruct *cfg)
{
    InstallSD(DEV,Ds1620Read,NULL,Ds1620Cntrl,FreeMemPtr);
    Ds1620Init(FreeMemPtr, cfg); 
    FreeMemPtr += sizeof(Ds1620CfgStruct);
    memcpy(FreeMemPtr,"***DsDat",8);
    FreeMemPtr += 8;
    return FreeMemPtr;
}

static void access1620(Ds1620CfgStruct *pCfg, UCHAR byInstuction, USHORT wPara, USHORT *wRtnValue)
{
    /* 如果要发送一条1620指令，需要先将复位引脚拉高，然后发出控制字，
       该引脚拉低之后表示一条指令的结束 */
    SetLLDat(&pCfg->Rst,1);
    delay1620();
    switch (byInstuction) {
        case DS1620_READ_TEMPERATURE:
            write1620(pCfg,DS1620_READ_TEMPERATURE, 8);
            *wRtnValue = read1620(pCfg,9);
            break;
        case DS1620_READ_COUNTER:
            write1620(pCfg,DS1620_READ_COUNTER, 8);
            *wRtnValue = read1620(pCfg,9);
            break;
        case DS1620_READ_SLOPE:
            write1620(pCfg,DS1620_READ_SLOPE, 8);
            *wRtnValue = read1620(pCfg,9);
            break;
        case DS1620_START_CONVERT_T:
            write1620(pCfg,DS1620_START_CONVERT_T, 8);
            break;
        case DS1620_STOP_CONVERT_T:
            write1620(pCfg,DS1620_STOP_CONVERT_T, 8);
            break;
        case DS1620_WRITE_TH:
            write1620(pCfg,DS1620_WRITE_TH, 8);
            write1620(pCfg,wPara, 9);
        /* 写指令结束之后需要延时10ms之后才可以继续工作。下同。*/
            tm_wkafter(1);
            break;
        case DS1620_WRITE_TL:
            write1620(pCfg,DS1620_WRITE_TL, 8);
            write1620(pCfg,wPara, 9);
            tm_wkafter(1);
            break;
        case DS1620_READ_TH:
            write1620(pCfg,DS1620_READ_TH, 8);
            *wRtnValue = read1620(pCfg,9);
            break;
        case DS1620_READ_TL:
            write1620(pCfg,DS1620_READ_TL, 8);
            *wRtnValue = read1620(pCfg,9);
            break;
        case DS1620_WRITE_CONFIG:
            write1620(pCfg,DS1620_WRITE_CONFIG, 8);
            write1620(pCfg,wPara, 8);
            break;
        case DS1620_READ_CONFIG:
            write1620(pCfg,DS1620_READ_CONFIG, 8);
            *wRtnValue = read1620(pCfg,8);
            break;
    }
    delay1620();
    SetLLDat(&pCfg->Rst,0);
    SetLLDat(&pCfg->Clk,0);            /* 保证1620处于连续转换状态 */
}

/******************************************************************************
* void write1620(pCfg,USHORT wCode, UCHAR byBits)                                *
*      Input:                                                                 *
*            wCode : 发向1620的设置控制字或者数据                             *
*            byBits: 控制字/数据的长度                                        *
******************************************************************************/
static void write1620(Ds1620CfgStruct *pCfg,USHORT wCode, UCHAR byBits)
{
    int     i;
    SetLLDat(&pCfg->Dir,1);
    for(i=0;i < byBits; i++){
    	int bit=(wCode & (1<<i))?1:0;
        SetLLDat(&pCfg->Clk,0);
        SetLLDat(&pCfg->Dq,bit);
        delay1620();
        SetLLDat(&pCfg->Clk,1);
        delay1620();
    }
}

/******************************************************************************
* USHORT read1620(pCfg,UCHAR byBits)                                             *
*      Input:                                                                 *
*            byBits: 待读取数据的长度                                         *
*      Return Value:                                                          *
*            读取的数据                                                       *
******************************************************************************/
static USHORT read1620(Ds1620CfgStruct *pCfg,UCHAR byBits)
{
    int    i;
    USHORT wValue = 0;
    SetLLDat(&pCfg->Dir,0);
    for(i=0;i < byBits; i++){
	SetLLDat(&pCfg->Clk,0);
        delay1620();
        wValue|=(GetLLDat(&pCfg->Dq)<<i);
	SetLLDat(&pCfg->Clk,1);
    }
    return wValue;
}

static void delay1620(void)
{
    volatile ULONG i=10;
    while (i--);
}