From 5d12f594303bdb76bf2356d9fc0661826e2e658e Mon Sep 17 00:00:00 2001
From: eZio Pan <eziopan@qq.com>
Date: Sat, 16 Mar 2024 00:25:38 +0800
Subject: [PATCH] stm32 CORDIC: make use of "preload" feature
---
embassy-stm32/src/cordic/mod.rs | 180 +++++++++++++++-----------------
1 file changed, 85 insertions(+), 95 deletions(-)
diff --git a/embassy-stm32/src/cordic/mod.rs b/embassy-stm32/src/cordic/mod.rs
index b15521ca6..997ace113 100644
--- a/embassy-stm32/src/cordic/mod.rs
+++ b/embassy-stm32/src/cordic/mod.rs
@@ -22,9 +22,8 @@ pub mod low_level {
/// CORDIC driver
pub struct Cordic<'d, T: Instance> {
- cordic: PeripheralRef<'d, T>,
+ peri: PeripheralRef<'d, T>,
config: Config,
- state: State,
}
/// CORDIC instance trait
@@ -83,23 +82,16 @@ impl<'d, T: Instance> Cordic<'d, T> {
/// Note:
/// If you need a periperhal -> CORDIC -> peripehral mode,
/// you may want to set Cordic into [Mode::ZeroOverhead] mode, and add extra arguemnts with [Self::extra_config]
- pub fn new(cordic: impl Peripheral<P = T> + 'd, config: Config) -> Self {
+ pub fn new(peri: impl Peripheral<P = T> + 'd, config: Config) -> Self {
T::enable_and_reset();
- into_ref!(cordic);
+ into_ref!(peri);
if !config.check_scale() {
panic!("Scale value is not compatible with Function")
}
- let mut instance = Self {
- cordic,
- config,
- state: State {
- input_buf: [0u32; 8],
- buf_index: 0,
- },
- };
+ let mut instance = Self { peri, config };
instance.reconfigure();
@@ -114,51 +106,71 @@ impl<'d, T: Instance> Cordic<'d, T> {
/// Set extra config for data count and data width.
pub fn extra_config(&mut self, arg_cnt: Count, arg_width: Width, res_width: Width) {
- let peri = &self.cordic;
- peri.set_argument_count(arg_cnt);
- peri.set_data_width(arg_width, res_width);
+ self.peri.set_argument_count(arg_cnt);
+ self.peri.set_data_width(arg_width, res_width);
}
fn reconfigure(&mut self) {
- let peri = &self.cordic;
- let config = &self.config;
-
- if peri.ready_to_read() {
+ if self.peri.ready_to_read() {
warn!("At least 1 result hasn't been read, reconfigure will cause DATA LOST");
};
- peri.disable_irq();
- peri.disable_write_dma();
- peri.disable_read_dma();
+ self.peri.disable_irq();
+ self.peri.disable_write_dma();
+ self.peri.disable_read_dma();
// clean RRDY flag
- while peri.ready_to_read() {
- peri.read_result();
+ while self.peri.ready_to_read() {
+ self.peri.read_result();
}
- peri.set_func(config.function);
- peri.set_precision(config.precision);
- peri.set_scale(config.scale);
+ self.peri.set_func(self.config.function);
+ self.peri.set_precision(self.config.precision);
+ self.peri.set_scale(self.config.scale);
- if config.first_result {
- peri.set_result_count(Count::One)
+ if self.config.first_result {
+ self.peri.set_result_count(Count::One)
} else {
- peri.set_result_count(Count::Two)
+ self.peri.set_result_count(Count::Two)
}
- match config.mode {
+ match self.config.mode {
Mode::ZeroOverhead => (),
Mode::Interrupt => {
- peri.enable_irq();
+ self.peri.enable_irq();
}
Mode::Dma => {
- peri.enable_write_dma();
- peri.enable_read_dma();
+ self.peri.enable_write_dma();
+ self.peri.enable_read_dma();
}
}
+ }
- self.state.input_buf.fill(0u32);
- self.state.buf_index = 0;
+ fn blocking_read_f64(&mut self) -> (f64, Option<f64>) {
+ let res1 = utils::q1_31_to_f64(self.peri.read_result());
+
+ let res2 = if !self.config.first_result {
+ Some(utils::q1_31_to_f64(self.peri.read_result()))
+ } else {
+ None
+ };
+
+ (res1, res2)
+ }
+
+ fn blocking_read_f64_to_buf(&mut self, result_buf: &mut [f64], result_index: &mut usize) {
+ let (res1, res2) = self.blocking_read_f64();
+ result_buf[*result_index] = res1;
+ *result_index += 1;
+
+ if let Some(res2) = res2 {
+ result_buf[*result_index] = res2;
+ *result_index += 1;
+ }
+ }
+
+ fn blocking_write_f64(&mut self, arg: f64) {
+ self.peri.write_argument(utils::f64_to_q1_31(arg));
}
}
@@ -172,11 +184,8 @@ impl<'d, T: Instance> Drop for Cordic<'d, T> {
impl<'d, T: Instance> Cordic<'d, T> {
/// Run a CORDIC calculation
pub fn calc_32bit(&mut self, arg1s: &[f64], arg2s: Option<&[f64]>, output: &mut [f64]) -> usize {
- let peri = &self.cordic;
- let config = &self.config;
-
assert!(
- match config.first_result {
+ match self.config.first_result {
true => output.len() >= arg1s.len(),
false => output.len() >= 2 * arg1s.len(),
},
@@ -185,87 +194,68 @@ impl<'d, T: Instance> Cordic<'d, T> {
self.check_input_f64(arg1s, arg2s);
- peri.set_result_count(if config.first_result { Count::One } else { Count::Two });
- peri.set_data_width(Width::Bits32, Width::Bits32);
+ self.peri.set_result_count(if self.config.first_result {
+ Count::One
+ } else {
+ Count::Two
+ });
- let state = &mut self.state;
+ self.peri.set_data_width(Width::Bits32, Width::Bits32);
let mut output_count = 0;
let mut consumed_input_len = 0;
- match config.mode {
+ match self.config.mode {
Mode::ZeroOverhead => {
// put double input into cordic
if arg2s.is_some() && !arg2s.unwrap().is_empty() {
let arg2s = arg2s.unwrap();
- peri.set_argument_count(Count::Two);
+ self.peri.set_argument_count(Count::Two);
- let double_value = arg1s.iter().zip(arg2s);
- consumed_input_len = double_value.len();
+ // Skip 1st value from arg1s, this value will be manually "preload" to cordic, to make use of cordic preload function.
+ // And we preserve last value from arg2s, since it need to manually write to cordic, and read the result out.
+ let double_input = arg1s.iter().skip(1).zip(&arg2s[..arg2s.len() - 1]);
+ // Since we preload 1st value from arg1s, the consumed input length is double_input length + 1.
+ consumed_input_len = double_input.len() + 1;
- for (arg1, arg2) in double_value {
- // if input_buf is full, send values to cordic
- if state.buf_index == INPUT_BUF_LEN - 1 {
- for arg in state.input_buf.chunks(2) {
- peri.write_argument(arg[0]);
- peri.write_argument(arg[1]);
+ // preload first value from arg1 to cordic
+ self.blocking_write_f64(arg1s[0]);
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
+ for (&arg1, &arg2) in double_input {
+ // Since we manually preload a value before,
+ // we will write arg2 (from the actual last pair) first, (at this moment, cordic start to calculating,)
+ // and write arg1 (from the actual next pair), then read the result, to "keep preloading"
- if !config.first_result {
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
- }
- }
-
- state.buf_index = 0;
- }
-
- for &&arg in [arg1, arg2].iter() {
- state.input_buf[state.buf_index] = utils::f64_to_q1_31(arg);
- state.buf_index += 1;
- }
+ self.blocking_write_f64(arg2);
+ self.blocking_write_f64(arg1);
+ self.blocking_read_f64_to_buf(output, &mut output_count);
}
- // put left paired args into cordic
- if state.buf_index > 0 {
- for arg in state.input_buf[..state.buf_index].chunks(2) {
- peri.write_argument(arg[0]);
- peri.write_argument(arg[1]);
-
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
-
- if !config.first_result {
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
- }
- }
-
- state.buf_index = 0;
- }
+ // write last input value from arg2s, then read out the result
+ self.blocking_write_f64(arg2s[arg2s.len() - 1]);
+ self.blocking_read_f64_to_buf(output, &mut output_count);
}
// put single input into cordic
let input_left = &arg1s[consumed_input_len..];
if !input_left.is_empty() {
- peri.set_argument_count(Count::One);
+ self.peri.set_argument_count(Count::One);
- for &arg in input_left.iter() {
- peri.write_argument(utils::f64_to_q1_31(arg));
+ // "preload" value to cordic (at this moment, cordic start to calculating)
+ self.blocking_write_f64(input_left[0]);
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
-
- if !config.first_result {
- output[output_count] = utils::q1_31_to_f64(peri.read_result());
- output_count += 1;
- }
+ for &arg in input_left.iter().skip(1) {
+ // this line write arg for next round caculation to cordic,
+ // and read result from last round
+ self.blocking_write_f64(arg);
+ self.blocking_read_f64_to_buf(output, &mut output_count);
}
+
+ // read the last output
+ self.blocking_read_f64_to_buf(output, &mut output_count);
}
output_count