diff options
Diffstat (limited to 'rfid_proto_tcl.c')
| -rw-r--r-- | rfid_proto_tcl.c | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/rfid_proto_tcl.c b/rfid_proto_tcl.c index a992f70..b8586f5 100644 --- a/rfid_proto_tcl.c +++ b/rfid_proto_tcl.c @@ -40,15 +40,33 @@ static unsigned int sfgi_to_sfgt(struct rfid_protocol_handle *h, unsigned char sfgi) { - /* ISO 14443-4:2000(E) Section 5.2.5. */ - return (256 * 16 / h->l2h->rh->ah->fc) * (2 ^ sfgi); + unsigned int multiplier; + + if (sfgi > 14) + sfgi = 14; + + multiplier = 1 << sfgi; /* 2 to the power of sfgi */ + + /* ISO 14443-4:2000(E) Section 5.2.5: + * (256 * 16 / h->l2h->rh->ah->fc) * (2 ^ sfgi) */ + + return (1000000 * 256*16 / h->l2h->rh->ah->fc) * multiplier; } static unsigned int fwi_to_fwt(struct rfid_protocol_handle *h, unsigned char fwi) { - /* ISO 14443-4:2000(E) Section 7.2. */ - return (256*16 / h->l2h->rh->ah->fc) * (2 ^ fwi); + unsigned int multiplier; + + if (fwi > 14) + fwi = 14; + + multiplier = 1 << fwi; /* 2 to the power of fwi */ + + /* ISO 14443-4:2000(E) Section 7.2.: + * (256*16 / h->l2h->rh->ah->fc) * (2 ^ fwi) */ + + return (1000000 * 256*16 / h->l2h->rh->ah->fc) * multiplier; } #define activation_fwt(x) (65536 / x->l2h->rh->ah->fc) |