From 84f9a525c64491afa9b7a565e3c10a4cee106e14 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Wed, 27 Jun 2012 17:17:44 -0700 Subject: [PATCH] altos: Clean up radio CRC handling Make the FEC code just set the CRC_OK bit like the cc1111 radio does; eliminates a bunch of weird conventions across the FEC API. Signed-off-by: Keith Packard --- src/core/ao.h | 7 +++++++ src/core/ao_fec.h | 2 ++ src/core/ao_fec_rx.c | 26 +++++++++++++++----------- src/drivers/ao_cc1120.c | 7 +------ src/drivers/ao_packet.c | 4 +--- src/test/ao_fec_test.c | 21 ++++++++++----------- 6 files changed, 36 insertions(+), 31 deletions(-) diff --git a/src/core/ao.h b/src/core/ao.h index 62eb488e..861a0fd4 100644 --- a/src/core/ao.h +++ b/src/core/ao.h @@ -511,6 +511,13 @@ extern __xdata uint8_t ao_radio_dma_done; extern __xdata uint8_t ao_radio_done; extern __xdata uint8_t ao_radio_mutex; +#ifdef PKT_APPEND_STATUS_1_CRC_OK +#define AO_RADIO_STATUS_CRC_OK PKT_APPEND_STATUS_1_CRC_OK +#else +#include +#define AO_RADIO_STATUS_CRC_OK AO_FEC_DECODE_CRC_OK +#endif + void ao_radio_general_isr(void) ao_arch_interrupt(16); diff --git a/src/core/ao_fec.h b/src/core/ao_fec.h index f1192b62..771732bd 100644 --- a/src/core/ao_fec.h +++ b/src/core/ao_fec.h @@ -70,6 +70,8 @@ ao_fec_encode(const uint8_t *in, uint8_t len, uint8_t *out); #define AO_FEC_DECODE_BLOCK (32) /* callback must return multiples of this many bits */ +#define AO_FEC_DECODE_CRC_OK 0x80 /* stored in out[out_len-1] */ + uint8_t ao_fec_decode(const uint8_t *in, uint16_t in_len, uint8_t *out, uint8_t out_len, uint16_t (*callback)()); diff --git a/src/core/ao_fec_rx.c b/src/core/ao_fec_rx.c index 0d400bb0..d4c98475 100644 --- a/src/core/ao_fec_rx.c +++ b/src/core/ao_fec_rx.c @@ -211,6 +211,7 @@ ao_fec_decode(const uint8_t *in, uint16_t len, uint8_t *out, uint8_t out_len, ui int8_t dist = b - (o + 8); /* distance to last ready-for-writing bit */ uint32_t min_cost; /* lowest cost */ uint8_t min_state; /* lowest cost state */ + uint8_t byte; /* Find the best fit at the current point * of the decode. @@ -238,24 +239,27 @@ ao_fec_decode(const uint8_t *in, uint16_t len, uint8_t *out, uint8_t out_len, ui printf ("\tbit %3d min_cost %5d old bit %3d old_state %x bits %02x whiten %0x\n", i/2, min_cost, o + 8, min_state, (bits[p][min_state] >> dist) & 0xff, *whiten); #endif - if (out_len) { - uint8_t byte = (bits[p][min_state] >> dist) ^ *whiten++; + byte = (bits[p][min_state] >> dist) ^ *whiten++; + *out++ = byte; + if (out_len > 2) + crc = ao_fec_crc_byte(byte, crc); - if (out_len > 2) { - crc = ao_fec_crc_byte(byte, crc); - *out++ = byte; - } else { - *out++ = byte ^ (crc >> 8); - crc <<= 8; - } - --out_len; + if (!--out_len) { + if ((out[-2] == (uint8_t) (crc >> 8)) && + out[-1] == (uint8_t) crc) + out[-1] = AO_FEC_DECODE_CRC_OK; + else + out[-1] = 0; + out[-2] = 0; + goto done; } o += 8; } } +done: #if AO_PROFILE ao_fec_decode_start = start_tick; ao_fec_decode_end = ao_profile_tick(); #endif - return len/16; + return 1; } diff --git a/src/drivers/ao_cc1120.c b/src/drivers/ao_cc1120.c index c974613e..30663042 100644 --- a/src/drivers/ao_cc1120.c +++ b/src/drivers/ao_cc1120.c @@ -690,12 +690,7 @@ ao_radio_recv(__xdata void *d, uint8_t size) ao_radio_put(); - /* Construct final packet */ - - if (ret && ((uint8_t *) d)[size] == 0 && ((uint8_t *)d)[size+1] == 0) - ((uint8_t *) d)[size + 1] = 0x80; - else - ((uint8_t *) d)[size + 1] = 0x00; + /* Store the received RSSI value; the crc-OK byte is already done */ ((uint8_t *) d)[size] = (uint8_t) rssi; diff --git a/src/drivers/ao_packet.c b/src/drivers/ao_packet.c index 19fe0558..28a0c415 100644 --- a/src/drivers/ao_packet.c +++ b/src/drivers/ao_packet.c @@ -65,10 +65,8 @@ ao_packet_recv(void) /* Check to see if we got a valid packet */ if (!dma_done) return 0; -#ifdef PKT_APPEND_STATUS_1_CRC_OK - if (!(ao_rx_packet.status & PKT_APPEND_STATUS_1_CRC_OK)) + if (!(ao_rx_packet.status & AO_RADIO_STATUS_CRC_OK)) return 0; -#endif /* Accept packets with matching call signs, or any packet if * our callsign hasn't been configured diff --git a/src/test/ao_fec_test.c b/src/test/ao_fec_test.c index 8ce532c8..671fcafc 100644 --- a/src/test/ao_fec_test.c +++ b/src/test/ao_fec_test.c @@ -268,18 +268,17 @@ int ao_real_packet(void) { uint8_t decode[64]; - uint8_t decode_len; - int ok = 0; + int ok; - decode_len = ao_fec_decode(real_packet, 576, decode, 34, NULL); + ok = ao_fec_decode(real_packet, 576, decode, 34, NULL); - if (decode[32] == 0 && decode[33] == 0) { + if (ok && decode[33] == AO_FEC_DECODE_CRC_OK) { printf ("match\n"); - ao_fec_dump_bytes(decode, decode_len, "Decode"); - ok = 1; + ao_fec_dump_bytes(decode, 34, "Decode"); } else { printf ("actual packet crc error\n"); + ok = 0; } return ok; } @@ -302,7 +301,7 @@ main(int argc, char **argv) int receive_len, receive_errors; uint8_t decode[DECODE_LEN(sizeof(original))]; - int decode_len; + int decode_ok; int errors = 0; int error; @@ -327,17 +326,17 @@ main(int argc, char **argv) receive_len = transmit_len; /* Decode it */ - decode_len = ao_fec_decode(receive, receive_len, decode, original_len + 2, NULL); + decode_ok = ao_fec_decode(receive, receive_len, decode, original_len + 2, NULL); /* Check to see if we received the right data */ error = 0; - if (decode_len < original_len + 2) { - printf ("len mis-match\n"); + if (!decode_ok) { + printf ("decode failed\n"); error++; } - if (decode[original_len] != 0 || decode[original_len+1] != 0) { + if (decode[original_len +1] != AO_FEC_DECODE_CRC_OK) { printf ("crc mis-match\n"); error++; } -- 2.30.2