dds: add frequency sweep

src/dds.rs

@@ -4,6 +4,7 @@ use core::mem::size_of;
 use core::convert::TryInto;
 use heapless::Vec;
 use heapless::consts::*;
+use log::{ trace, debug, warn };
 
 /*
  *  Bitmask for all configurations (Order: CFR3, CFR2, CFR1)
@@ -634,6 +635,77 @@ where
             no_dwell_high, zero_crossing, op_mode, playback_rate)
 	}
 	
+    /*
+     *  Configure a frequency sweep RAM mode profile
+     */
+	pub unsafe fn set_frequency_sweep_profile(&mut self, profile: u8, start_addr: u16,
+        lower_boundary: f64, upper_boundary: f64, f_resolution: f64,
+        no_dwell_high: bool, op_mode: RAMOperationMode, playback_rate: f64
+    ) -> Result<(), Error<E>> {
+
+        // Check the legality of the profile setup
+        assert!(profile <= 7);
+        assert!(start_addr < 1024);
+
+        // Find out the required RAM size
+        // Frequencies may have to be repeated if the playback rate is too low
+        // Reject impossible setups
+        // E.g. Higher playback rate than f_dds_clk, insufficient RAM allocation
+        let nominal_step_rate = self.f_sys_clk/(4.0 * playback_rate);
+        if nominal_step_rate < 1.0 {
+            return Err(Error::DDSRAMError);
+        }
+
+        // TODO: Handle unfortunate scenario: step_rate / 0xFFFF gives a round number
+        // Current implmentation unnecessarily allocates 1 extra RAM space for each data
+        let duplication = (nominal_step_rate / (0xFFFF as f64)) as u64 + 1;
+
+        // Acquire the RAM size needed by multiplying duplication.
+        // All data needs to be duplicated such that a desired step_rate can be reached
+        // Return DDS RAM Error if it does not fix into the RAM
+        let span = upper_boundary - lower_boundary;
+        let data_size = if core::intrinsics::roundf64(span/f_resolution) == (span/f_resolution) {
+                (span/f_resolution) as u64 + 1
+        } else {
+                (span/f_resolution) as u64
+        };
+        let ram_size = data_size * duplication;
+
+        let end_addr = (start_addr as u64) + ram_size - 1;
+        trace!("Required RAM size: {}", ram_size);
+        if end_addr >= 1024 {
+            warn!("RAM address out of bound");
+            return Err(Error::DDSRAMError);
+        }
+
+        // Clear RAM vector, and add address byte
+        RAM_VEC.clear();
+        RAM_VEC.push(0x16)
+            .map_err(|_| Error::DDSRAMError)?;
+
+        // Drop in the data into RAM_VEC
+        for data_index in 0..data_size {
+            let freq = lower_boundary + f_resolution * (data_index as f64);
+            for _ in 0..duplication {
+                let ftw = self.frequency_to_ftw(freq);
+                RAM_VEC.push(((ftw >> 24) & 0xFF) as u8)
+                    .map_err(|_| Error::DDSRAMError)?;
+                RAM_VEC.push(((ftw >> 16) & 0xFF) as u8)
+                    .map_err(|_| Error::DDSRAMError)?;
+                RAM_VEC.push(((ftw >>  8) & 0xFF) as u8)
+                    .map_err(|_| Error::DDSRAMError)?;
+                RAM_VEC.push(((ftw >>  0) & 0xFF) as u8)
+                    .map_err(|_| Error::DDSRAMError)?;
+            }
+        }
+
+        debug!("start_addr: {}\nend_addr: {}\n, duplication: {}\n, data_size: {}\n",
+            start_addr, end_addr, duplication, data_size);
+
+        self.set_ram_profile(profile, start_addr, end_addr.try_into().unwrap(), RAMDestination::Frequency,
+            no_dwell_high, true, op_mode, playback_rate * (duplication as f64))
+    }
+
     /*
      *  Configure a RAM mode profile, w.r.t static vector (RAM_VEC)
      */
@@ -650,6 +722,7 @@ where
 
         // Calculate address step rate, and check legality
         let step_rate = (self.f_sys_clk/(4.0 * playback_rate)) as u64;
+        trace!("Setting up RAM profile, step_rate: {}", step_rate);
         if step_rate == 0 || step_rate > 0xFFFF {
             return Err(Error::DDSRAMError);
         }
@@ -729,9 +802,9 @@ where
 
     // Setter function for f_sys_clk
     // Warning: This does not setup the chip to generate this actual f_sys_clk
-    pub(crate) fn set_f_sys_clk(&mut self, f_sys_clk: f64) {
-        self.f_sys_clk = f_sys_clk;
-    }
+    // pub(crate) fn set_f_sys_clk(&mut self, f_sys_clk: f64) {
+    //     self.f_sys_clk = f_sys_clk;
+    // }
 
     // Getter function for f_sys_clk
     pub fn get_f_sys_clk(&mut self) -> f64 {

src/urukul.rs

@@ -7,7 +7,7 @@ use crate::config_register::ConfigRegister;
 use crate::config_register::CFGMask;
 use crate::config_register::StatusMask;
 use crate::attenuator::Attenuator;
-use crate::dds::DDS;
+use crate::dds::{ DDS, RAMOperationMode };
 
 /*
  * Enum for structuring error
@@ -278,6 +278,16 @@ where
         self.dds[usize::from(channel)].set_single_tone_profile_amplitude(profile, amplitude)
     }
 
+    pub fn set_channel_frequency_sweep_profile(&mut self, channel: u8, profile: u8, start_addr: u16, lower_boundary: f64,
+        upper_boundary: f64, f_resolution: f64, playback_rate: f64) -> Result<(), Error<E>>
+    {
+        unsafe {
+            self.dds[usize::from(channel)]
+                .set_frequency_sweep_profile(profile, start_addr, lower_boundary, upper_boundary,
+                f_resolution, true, RAMOperationMode::ContinuousRecirculate, playback_rate)
+        }
+    }
+
     pub fn set_channel_sys_clk(&mut self, channel: u8, f_sys_clk: f64) -> Result<(), Error<E>> {
         self.dds[usize::from(channel)].set_sys_clk_frequency(f_sys_clk).map(|_| ())
     }
@@ -320,8 +330,7 @@ where
         }
         self.multi_dds.set_sys_clk_frequency(reported_f_sys_clk)?;
         self.multi_dds.set_single_tone_profile(profile, frequency, phase, amplitude)?;
-        self.invoke_io_update()?;
-        Ok(())
+        self.invoke_io_update()
     }
 
     // Generate a pulse for io_update bit in configuration register