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fix coverity 294113

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This commit is contained in:
iceman1001 2020-07-11 20:53:07 +02:00
commit ebb7eb9f3e
1 changed files with 31 additions and 40 deletions
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17
armsrc/em4x50.c
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@ -100,7 +100,6 @@ int gLow = 0;
static void init_tag(void) {
// initialize global tag structure
for (int i = 0; i < 34; i++)
for (int j = 0; j < 7; j++)
tag.sectors[i][j] = 0x00;
@ -109,9 +108,7 @@ static void init_tag(void) {
static uint8_t bits2byte(uint8_t *bits, int length) {
// converts <length> separate bits into a single "byte"
uint8_t byte = 0;
for (int i = 0; i < length; i++) {
byte |= bits[i];
@ -128,7 +125,6 @@ static void msb2lsb_word(uint8_t *word) {
// reorders given <word> according to EM4x50 datasheet (msb -> lsb)
uint8_t buff[4];
buff[0] = reflect8(word[3]);
buff[1] = reflect8(word[2]);
buff[2] = reflect8(word[1]);
@ -144,7 +140,6 @@ static void save_word(int pos, uint8_t bits[EM4X50_TAG_WORD]) {
// split "raw" word into data, row and column parity bits and stop bit and
// save them in global tag structure
uint8_t row_parity[4];
uint8_t col_parity[8];
@ -186,7 +181,6 @@ static void wait_timer(int timer, uint32_t period) {
static void em4x50_setup_read(void) {
FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_ADC | FPGA_LF_ADC_READER_FIELD);
// 50ms for the resonant antenna to settle.
@ -245,11 +239,11 @@ static bool get_signalproperties(void) {
bool signal_found = false;
int no_periods = 32, pct = 75, noise = 140;
uint8_t sample = 0, sample_ref = 127;
uint8_t sample_ref = 127;
uint8_t sample_max_mean = 0;
uint8_t sample_max[no_periods];
uint32_t sample_max_sum = 0;
memcpy(sample_max, 0x00, sizeof(sample_max));
// wait until signal/noise > 1 (max. 32 periods)
for (int i = 0; i < T0 * no_periods; i++) {
@ -274,7 +268,7 @@ static bool get_signalproperties(void) {
AT91C_BASE_TC0->TC_CCR = AT91C_TC_SWTRG;
while (AT91C_BASE_TC0->TC_CV < T0 * 3 * EM4X50_T_TAG_FULL_PERIOD) {
sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
volatile uint8_t sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if (sample > sample_max[i])
sample_max[i] = sample;
@ -289,7 +283,6 @@ static bool get_signalproperties(void) {
// set global envelope variables
gHigh = sample_ref + pct * (sample_max_mean - sample_ref) / 100;
gLow = sample_ref - pct * (sample_max_mean - sample_ref) / 100;
return true;
}
@ -301,11 +294,9 @@ static int get_next_bit(void) {
// a listen window (return value = EM4X50_BIT_OTHER) in functions
// "find_double_listen_window" and "check_ack"
uint8_t sample;
// get sample at 3/4 of bit period
wait_timer(0, T0 * EM4X50_T_TAG_THREE_QUARTER_PERIOD);
sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
uint8_t sample = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
// wait until end of bit period
wait_timer(0, T0 * EM4X50_T_TAG_QUARTER_PERIOD);