anticollselect.c

飞利浦RC522芯片源代码。该芯片主要针对三表市场和手持设备

/*************************************************
Function:       AnticollSelect
Description:
     Anticollision loop and selecte a card to operate
Parameter:
     bcnt       bit counter of known UID
     snr        buffer to store the card UID
Return:
     short      status of implement
**************************************************/
short AnticollSelect(unsigned char bcnt, unsigned char *snr)
{
    unsigned char i;
    short status=STATUS_SUCCESS;
    unsigned char length, casc_code, length_in,sak,tmpSnr[12];
    length_in = bcnt;
    /* do loop for max. cascade level */
    for(i=0;i<MAX_CASCADE_LEVELS;i++)
    {
        if(length_in)
        {
            if(length_in > SINGLE_UID_LENGTH)
            {
                length = SINGLE_UID_LENGTH;
                length_in -= SINGLE_UID_LENGTH;
            }
            else
            {
                length = length_in;
                length_in = 0;
            }
        }
        else
        {
            length = 0;
        }

        switch(i)
        {
            case 1:  casc_code = SELECT_CASCADE_LEVEL_2;
                     memcpy(snr, tmpSnr+1,3);
                     break;
            case 2:  casc_code = SELECT_CASCADE_LEVEL_3;
                     break;
            default: casc_code = SELECT_CASCADE_LEVEL_1;
                     break;
        }

        if(length != SINGLE_UID_LENGTH && status == STATUS_SUCCESS)
        /* do anticollission with selected level */
        status = CascAnticoll(casc_code,
                              length,
                              tmpSnr + i * 4);