fixed ISO 14443A anticollision

[librfid] / src / rfid_asic_rc632.c

diff --git a/src/rfid_asic_rc632.c b/src/rfid_asic_rc632.c
index 0d6824c..0560d09 100644 (file)
--- a/src/rfid_asic_rc632.c
+++ b/src/rfid_asic_rc632.c
@@ -875,7 +875,7 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle,
        int ret;
        u_int8_t rx_buf[64];
        u_int8_t rx_len = sizeof(rx_buf);
-       u_int8_t rx_align = 0, tx_last_bits, tx_bytes;
+       u_int8_t rx_align = 0, tx_last_bits, tx_bytes, tx_bytes_total;
        u_int8_t boc;
        u_int8_t error_flag;
        *bit_of_col = ISO14443A_BITOFCOL_NONE;
@@ -899,14 +899,14 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle,
        if (ret < 0)
                return ret;
 
-       tx_last_bits = acf->nvb & 0x0f; /* lower nibble indicates bits */
-       tx_bytes = acf->nvb >> 4;
+       tx_last_bits = acf->nvb & 0x07; /* lower nibble indicates bits */
+       tx_bytes = ( acf->nvb >> 4 ) & 0x07;
        if (tx_last_bits) {
-               tx_bytes++;
-               rx_align = (tx_last_bits+1) % 8;/* rx frame complements tx */
+               tx_bytes_total = tx_bytes+1;
+               rx_align = tx_last_bits & 0x07; /* rx frame complements tx */
        }
-
-       //rx_align = 8 - tx_last_bits;/* rx frame complements tx */
+       else
+               tx_bytes_total = tx_bytes;
 
        /* set RxAlign and TxLastBits*/
        ret = rc632_reg_write(handle, RC632_REG_BIT_FRAMING,
@@ -914,7 +914,7 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle,
        if (ret < 0)
                return ret;
 
-       ret = rc632_transceive(handle, (u_int8_t *)acf, tx_bytes,
+       ret = rc632_transceive(handle, (u_int8_t *)acf, tx_bytes_total,
                                rx_buf, &rx_len, 0x32, 0);
        if (ret < 0)
                return ret;
@@ -923,8 +923,10 @@ rc632_iso14443a_transceive_acf(struct rfid_asic_handle *handle,
        acf->uid_bits[tx_bytes-2] = (
                  (acf->uid_bits[tx_bytes-2] & (0xff >> (8-tx_last_bits)))
                | rx_buf[0]);
+       
        /* copy the rest */
-       memcpy(&acf->uid_bits[tx_bytes+1-2], &rx_buf[1], rx_len-1);
+       if(rx_len)
+           memcpy(&acf->uid_bits[tx_bytes-1], &rx_buf[1], rx_len-1);
 
        /* determine whether there was a collission */
        ret = rc632_reg_read(handle, RC632_REG_ERROR_FLAG, &error_flag);