From faba586311d85a3c99d39b7b44323d0830f75a07 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Hamal=20Dvo=C5=99=C3=A1k?= <mordae@anilinux.org>
Date: Sun, 25 Feb 2024 23:15:58 +0100
Subject: [PATCH] Assume decimation and optimize the loops
---
src/main.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)
diff --git a/src/main.c b/src/main.c
index dbd959a..6950eca 100644
--- a/src/main.c
+++ b/src/main.c
@@ -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;