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CC2420: Doing CRC in hardware all the time

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This commit is contained in:
kkrentz 2013-05-24 03:04:17 -07:00
parent 515287ef17
commit 9e266acd9c
1 changed files with 23 additions and 60 deletions
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73
dev/cc2420/cc2420.c
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@ -52,12 +52,6 @@
#define WITH_SEND_CCA 1
#define FOOTER_LEN 2
#ifndef CC2420_CONF_CHECKSUM
#define CC2420_CONF_CHECKSUM 0
#endif /* CC2420_CONF_CHECKSUM */
#ifndef CC2420_CONF_CHANNEL
#define CC2420_CONF_CHANNEL 26
#endif /* CC2420_CONF_CHANNEL */
@ -66,21 +60,12 @@
#define CC2420_CONF_CCA_THRESH -45
#endif /* CC2420_CONF_CCA_THRESH */
#ifndef CC2420_CONF_AUTOACK
#define CC2420_CONF_AUTOACK 0
#endif /* CC2420_CONF_AUTOACK */
#if CC2420_CONF_CHECKSUM
#include "lib/crc16.h"
#define CHECKSUM_LEN 2
#else
#define CHECKSUM_LEN 0
#endif /* CC2420_CONF_CHECKSUM */
#define AUX_LEN (CHECKSUM_LEN + FOOTER_LEN)
#define CHECKSUM_LEN 2
#define FOOTER_LEN 2
#define FOOTER1_CRC_OK 0x80
#define FOOTER1_CORRELATION 0x7f
@ -422,6 +407,7 @@ set_txpower(uint8_t power)
}
/*---------------------------------------------------------------------------*/
#define AUTOACK (1 << 4)
#define AUTOCRC (1 << 5)
#define ADR_DECODE (1 << 11)
#define RXFIFO_PROTECTION (1 << 9)
#define CORR_THR(n) (((n) & 0x1f) << 6)
@ -460,6 +446,12 @@ cc2420_init(void)
#else
reg &= ~(AUTOACK | ADR_DECODE);
#endif /* CC2420_CONF_AUTOACK */
/* Enabling CRC in hardware; this is required by AUTOACK anyway
and provides us with RSSI and link quality indication (LQI)
information. */
reg |= AUTOCRC;
setreg(CC2420_MDMCTRL0, reg);
/* Set transmission turnaround time to the lower setting (8 symbols
@ -498,9 +490,6 @@ static int
cc2420_transmit(unsigned short payload_len)
{
int i, txpower;
#if CC2420_CONF_CHECKSUM
uint16_t checksum;
#endif /* CC2420_CONF_CHECKSUM */
GET_LOCK();
@ -599,9 +588,7 @@ static int
cc2420_prepare(const void *payload, unsigned short payload_len)
{
uint8_t total_len;
#if CC2420_CONF_CHECKSUM
uint16_t checksum;
#endif /* CC2420_CONF_CHECKSUM */
GET_LOCK();
PRINTF("cc2420: sending %d bytes\n", payload_len);
@ -614,15 +601,9 @@ cc2420_prepare(const void *payload, unsigned short payload_len)
/* Write packet to TX FIFO. */
strobe(CC2420_SFLUSHTX);
#if CC2420_CONF_CHECKSUM
checksum = crc16_data(payload, payload_len, 0);
#endif /* CC2420_CONF_CHECKSUM */
total_len = payload_len + AUX_LEN;
total_len = payload_len + CHECKSUM_LEN;
CC2420_WRITE_FIFO_BUF(&total_len, 1);
CC2420_WRITE_FIFO_BUF(payload, payload_len);
#if CC2420_CONF_CHECKSUM
CC2420_WRITE_FIFO_BUF(&checksum, CHECKSUM_LEN);
#endif /* CC2420_CONF_CHECKSUM */
RELEASE_LOCK();
return 0;
@ -796,11 +777,8 @@ PROCESS_THREAD(cc2420_process, ev, data)
static int
cc2420_read(void *buf, unsigned short bufsize)
{
uint8_t footer[2];
uint8_t footer[FOOTER_LEN];
uint8_t len;
#if CC2420_CONF_CHECKSUM
uint16_t checksum;
#endif /* CC2420_CONF_CHECKSUM */
if(!CC2420_FIFOP_IS_1) {
return 0;
@ -825,49 +803,34 @@ cc2420_read(void *buf, unsigned short bufsize)
return 0;
}
if(len <= AUX_LEN) {
if(len <= FOOTER_LEN) {
flushrx();
RIMESTATS_ADD(tooshort);
RELEASE_LOCK();
return 0;
}
if(len - AUX_LEN > bufsize) {
if(len - FOOTER_LEN > bufsize) {
flushrx();
RIMESTATS_ADD(toolong);
RELEASE_LOCK();
return 0;
}
getrxdata(buf, len - AUX_LEN);
#if CC2420_CONF_CHECKSUM
getrxdata(&checksum, CHECKSUM_LEN);
#endif /* CC2420_CONF_CHECKSUM */
getrxdata(buf, len - FOOTER_LEN);
getrxdata(footer, FOOTER_LEN);
#if CC2420_CONF_CHECKSUM
if(checksum != crc16_data(buf, len - AUX_LEN, 0)) {
PRINTF("checksum failed 0x%04x != 0x%04x\n",
checksum, crc16_data(buf, len - AUX_LEN, 0));
}
if(footer[1] & FOOTER1_CRC_OK &&
checksum == crc16_data(buf, len - AUX_LEN, 0)) {
#else
if(footer[1] & FOOTER1_CRC_OK) {
#endif /* CC2420_CONF_CHECKSUM */
cc2420_last_rssi = footer[0];
cc2420_last_correlation = footer[1] & FOOTER1_CORRELATION;
packetbuf_set_attr(PACKETBUF_ATTR_RSSI, cc2420_last_rssi);
packetbuf_set_attr(PACKETBUF_ATTR_LINK_QUALITY, cc2420_last_correlation);
RIMESTATS_ADD(llrx);
} else {
RIMESTATS_ADD(badcrc);
len = AUX_LEN;
len = FOOTER_LEN;
}
if(CC2420_FIFOP_IS_1) {
@ -884,11 +847,11 @@ cc2420_read(void *buf, unsigned short bufsize)
RELEASE_LOCK();
if(len < AUX_LEN) {
if(len < FOOTER_LEN) {
return 0;
}
return len - AUX_LEN;
return len - FOOTER_LEN;
}
/*---------------------------------------------------------------------------*/
void