diff options
Diffstat (limited to 'openpicc/application/iso14443_layer3a.h')
| -rw-r--r-- | openpicc/application/iso14443_layer3a.h | 53 |
1 files changed, 52 insertions, 1 deletions
diff --git a/openpicc/application/iso14443_layer3a.h b/openpicc/application/iso14443_layer3a.h index 6f32dd5..142128e 100644 --- a/openpicc/application/iso14443_layer3a.h +++ b/openpicc/application/iso14443_layer3a.h @@ -15,6 +15,7 @@ enum ISO14443_STATES { ERROR, /* Some unrecoverable error has occured */ }; +/******************** RX ************************************/ /* standard derived magic values */ #define ISO14443A_FDT_SHORT_1 1236 #define ISO14443A_FDT_SHORT_0 1172 @@ -30,6 +31,15 @@ enum ISO14443_STATES { #define ISO14443A_SOF_LEN 4 /* Length in samples of a short frame */ #define ISO14443A_SHORT_LEN 32 +/* This is wrong: a short frame is 1 start bit, 7 data bits, 1 stop bit + * followed by no modulation for one bit period. The start bit is 'eaten' in + * SSC Compare 0, but the remaining 7+1+1 bit durations must be sampled and + * compared. At four times oversampling this would be 9*4=36 samples, which is + * more than one SSC transfer. You'd have to use two transfers of 18 samples + * each and modify the comparison code accordingly. + * Since four times oversampling doesn't work reliably anyway (every second + * sample is near an edge and might sample 0 or 1) this doesn't matter for now.*/ +#error Four times oversampling is broken, see comments in code #else /* definitions for two-times oversampling */ @@ -38,8 +48,49 @@ enum ISO14443_STATES { #define ISO14443A_SOF_SAMPLE 0x01 #define ISO14443A_SOF_LEN 2 -#define ISO14443A_SHORT_LEN 16 +#define ISO14443A_SHORT_LEN 18 #endif +/* A short frame should be received in one single SSC transfer */ +#if (ISO14443A_SHORT_LEN <= 8) +/* SSC transfer size in bits */ +#define ISO14443A_SHORT_TRANSFER_SIZE 8 +#define ISO14443A_SHORT_TYPE u_int8_t + +#elif (ISO14443A_SHORT_LEN <= 16) +#define ISO14443A_SHORT_TRANSFER_SIZE 16 +#define ISO14443A_SHORT_TYPE u_int16_t + +#elif (ISO14443A_SHORT_LEN <= 32) +#define ISO14443A_SHORT_TRANSFER_SIZE 32 +#define ISO14443A_SHORT_TYPE u_int32_t + +#else +#error ISO14443A_SHORT_LEN defined too big +#endif + +/******************** TX ************************************/ +/* in bytes, not counting parity */ +#define MAXIMUM_FRAME_SIZE 256 + +typedef struct { + enum { TYPE_A, TYPE_B } type; + union { + struct { + enum { SHORT_FRAME, STANDARD_FRAME, AC_FRAME } format; + enum { PARITY, /* Calculate parity on the fly, ignore the parity field below */ + GIVEN_PARITY, /* Use the parity bits from the parity field below */ + NO_PARITY, /* Don't send any parity */ + } parity; + } a; + } parameters; + u_int32_t numbytes; + u_int8_t numbits, bit_offset; + u_int8_t data[MAXIMUM_FRAME_SIZE]; + u_int8_t parity[MAXIMUM_FRAME_SIZE]; /* Only the LSB of each byte is used */ +} iso14443_frame; + +extern const iso14443_frame ATQA_FRAME; + #endif /*ISO14443_LAYER3A_H_*/ |