mordae/pico-sdr
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Assume decimation and optimize the loops

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Jan Hamal Dvořák 2024-02-25 23:15:58 +01:00
parent b3422c5674
commit faba586311
1 changed files with 16 additions and 17 deletions
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33
src/main.c
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@ -43,7 +43,6 @@
#define LPF_SIZE DECIMATION
#define IQ_BLOCK_LEN 64
#define RX_BLOCK_LEN (IQ_BLOCK_LEN * DECIMATION)
#define XOR_ADDR 0x1000
#define LO_COS_ACCUMULATOR (&pio1->sm[2].pinctrl)
@ -62,7 +61,7 @@ static uint32_t rx_sin[RX_WORDS] __attribute__((__aligned__(RX_WORDS * 4)));
#define SIN_PHASE (UINT_MAX / 4)
#define COS_PHASE (0)
static_assert(RX_WORDS > RX_BLOCK_LEN, "RX buffers too short for given decimation");
static_assert(RX_WORDS > 2 * DECIMATION, "RX buffers too short for given decimation");
/* rx -> cp -> cos -> sin -> pio_cos -> pio_sin -> rx ... */
static int dma_ch_rx = -1;
@ -580,24 +579,24 @@ static void rf_rx(void)
return;
}
int delta = prev_transfers - dma_hw->ch[dma_ch_in_cos].transfer_count;
gap = RX_BLOCK_LEN - delta;
while (delta < RX_BLOCK_LEN) {
delta = prev_transfers - dma_hw->ch[dma_ch_in_cos].transfer_count;
sleep_us(100);
}
prev_transfers -= RX_BLOCK_LEN;
uint32_t *cos_ptr = rx_cos + pos;
uint32_t *sin_ptr = rx_sin + pos;
pos = (pos + RX_BLOCK_LEN) & (RX_WORDS - 1);
int8_t *blockptr = block;
for (int i = 0; i < IQ_BLOCK_LEN / 2; i++) {
int delta = prev_transfers - dma_hw->ch[dma_ch_in_cos].transfer_count;
gap = 2 * DECIMATION - delta;
while (delta < 2 * DECIMATION) {
delta = prev_transfers - dma_hw->ch[dma_ch_in_cos].transfer_count;
sleep_us(100);
}
prev_transfers -= 2 * DECIMATION;
uint32_t *cos_ptr = rx_cos + pos;
uint32_t *sin_ptr = rx_sin + pos;
pos = (pos + 2 * DECIMATION) & (RX_WORDS - 1);
int64_t dI = 0;
int64_t dQ = 0;