diff options
| author | Gary E. Miller <gem@rellim.com> | 2010-04-14 00:22:36 -0700 |
|---|---|---|
| committer | Gary E. Miller <gem@rellim.com> | 2010-04-14 00:22:36 -0700 |
| commit | 377f18439013d69c049cc0a3c8941d2351476658 (patch) | |
| tree | 5490da7540a27365adee75ef9830d971d24b5df7 /driver_sirf.c | |
| parent | 00acffa2b1f2290bc1bb301d8110dbca3bf84111 (diff) | |
| download | gpsd-377f18439013d69c049cc0a3c8941d2351476658.tar.gz | |
Tweak the 50BPS inversion algorith.
Diffstat (limited to 'driver_sirf.c')
| -rw-r--r-- | driver_sirf.c | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/driver_sirf.c b/driver_sirf.c index 44e90ea3..d6ccf1a4 100644 --- a/driver_sirf.c +++ b/driver_sirf.c @@ -433,27 +433,24 @@ static gps_mask_t sirf_msg_navdata(struct gps_device_t *session, unsigned char * preamble = words[0] >> 16; if (preamble == 0x8b){ preamble ^= 0xff; - words[0] ^= 0xffffff; } parity1 = parity9 = 0; - for (i = 1; i < 10; i++) { + for (i = 0; i < 10; i++) { int invert; words[i] = (unsigned int)getbeul(buf, 4*i + 3); invert = (words[i] & 0x40000000) ? 1 : 0; - if (i == 1) { - parity1 = words[1] & 0x3; - if (!invert) - parity1 ^= 0x3; - } - if (i == 9) { - parity9 = words[9] & 0x3; - if (!invert) - parity9 ^= 0x3; - } /* inverted the data, invert it back */ if (invert) words[i] ^= 0xffffffff; + switch( i ) { + case 1: + parity1 = words[1] & 0x3; + break; + case 9: + parity9 = words[9] & 0x3; + break; + } words[i] = (words[i] & 0x3fffffff) >> 6; } gpsd_report(LOG_PROG, "SiRF: 50BPS 0x08: %2d %2d " |