dds: add clock control

src/attenuator.rs

@@ -1,5 +1,4 @@
 use embedded_hal::blocking::spi::Transfer;
-use cortex_m::asm::nop;
 use cortex_m_semihosting::hprintln;
 use core::assert;
 

src/bitmask_macro.rs

@@ -1,5 +1,3 @@
-use core::mem::size_of;
-
 /*
  * Macro builder for bit masks
  * $collection: Name for the bit mask collection

src/config_register.rs

@@ -78,7 +78,7 @@ where
 	 * Return selected configuration field
 	 */
 	pub fn get_configuration(&mut self, config_type: CFGMask) -> u8 {
-		(config_type.get_filtered_content(self.data) as u8)
+		config_type.get_filtered_content(self.data) as u8
 	}
 
 	/*

src/dds.rs

@@ -65,15 +65,17 @@ const READ_MASK		:u8 = 0x80;
 
 pub struct DDS<SPI> {
 	spi: SPI,
+	f_ref_clk: u64,
 }
 
 impl<SPI, E> DDS<SPI>
 where
 	SPI: Transfer<u8, Error = E>
 {
-	pub fn new(spi: SPI) -> Self {
+	pub fn new(spi: SPI, f_ref_clk: u64) -> Self {
 		DDS {
-			spi
+			spi,
+			f_ref_clk,
 		}
 	}
 }
@@ -89,13 +91,14 @@ where
 	}
 }
 
-/*
- *  Implement init
- */
+
 impl<SPI, E> DDS<SPI>
 where
 	SPI: Transfer<u8, Error = E>
 {
+	/*
+	 *  Implement init: Set SDIO to be input only, using LSB first
+	 */
 	pub fn init(&mut self) -> Result<(), Error<E>> {
 		match self.write_register(0x00, &mut [
 			0x00, 0x00, 0x00, 0x02
@@ -104,17 +107,81 @@ where
 			Err(e) => Err(e),
 		}
 	}
+
+	/*
+	 *  Implement clock control
+	 */
+	pub fn enable_divided_ref_clk(&mut self) -> Result<(), Error<E>> {
+		self.set_configurations(&mut [
+			// Disable PLL
+			(DDSCFRMask::PLL_ENABLE, 0),
+			// Take ref_clk source from divider
+			(DDSCFRMask::REFCLK_IN_DIV_BYPASS, 0),
+			// Ensure divider is not reset
+			(DDSCFRMask::REFCLK_IN_DIV_RESETB, 1),
+		])
+	}
+
+	pub fn enable_normal_ref_clk(&mut self) -> Result<(), Error<E>> {
+		self.set_configurations(&mut [
+			// Disable PLL
+			(DDSCFRMask::PLL_ENABLE, 0),
+			// Take ref_clk source from divider bypass
+			(DDSCFRMask::REFCLK_IN_DIV_BYPASS, 1),
+			// Reset does not matter
+			(DDSCFRMask::REFCLK_IN_DIV_RESETB, 1),
+		])
+	}
+
+	pub fn enable_pll(&mut self, f_sys_clk: u64) -> Result<(), Error<E>> {
+		// Get a divider
+		let divider = f_sys_clk / self.f_ref_clk;
+		// Reject extreme divider values. However, accept no frequency division
+		if ((divider > 127 || divider < 12) && divider != 1) {
+			panic!("Invalid divider value for PLL!");
+		}
+		// Select a VCO
+		let vco = if divider == 1 {
+			6	// Bypass PLL if no frequency division needed
+		} else if f_sys_clk > 1_150_000_000 {
+			panic!("Invalid divider value for PLL!")
+		} else if f_sys_clk > 820_000_000 {
+			5
+		} else if f_sys_clk > 700_000_000 {
+			4
+		} else if f_sys_clk > 600_000_000 {
+			3
+		} else if f_sys_clk > 500_000_000 {
+			2
+		} else if f_sys_clk > 420_000_000 {
+			1
+		} else if f_sys_clk > 370_000_000 {
+			0
+		} else {
+			7	// Bypass PLL if f_sys_clk is too low
+		};
+		self.set_configurations(&mut [
+			// Enable PLL, set divider (valid or not) and VCO
+			(DDSCFRMask::PLL_ENABLE, 1),
+			(DDSCFRMask::N, divider as u32),
+			(DDSCFRMask::VCO_SEL, vco),
+			// Reset PLL lock before re-enabling it
+			(DDSCFRMask::PFD_RESET, 1),
+		])?;
+		self.set_configurations(&mut [
+			(DDSCFRMask::PFD_RESET, 0),
+		])
+	}
+
+	// Change external clock source (ref_clk)
+	pub fn set_ref_clk_frequency(&mut self, f_ref_clk: u64) {
+		self.f_ref_clk = f_ref_clk;
 	}
 
 	/*
 	 *  Impleement configurations registers I/O through bitmasks
- */
-impl<SPI, E> DDS<SPI>
-where
-	SPI: Transfer<u8, Error = E>
-{
-	/*
-	 *  Return (cfr1, cfr2, cfr3) contents
+	 *
+	 *  Get all (cfr1, cfr2, cfr3) contents
 	 */
 	fn get_all_configurations(&mut self) -> Result<[u32; 3], Error<E>> {
 		let mut cfr_reg = [0; 12];
@@ -164,9 +231,8 @@ where
 	 */
 	pub fn set_configurations(&mut self, mask_pairs: &mut[(DDSCFRMask, u32)]) -> Result<(), Error<E>> {
 		let mut data_array = self.get_all_configurations()?;
-		hprintln!("Initial array {:#X?}", data_array).unwrap();
 		for index in 0..mask_pairs.len() {
-			// Reject any attempt to write LSB_FIRST and SBIO_INPUT_ONLY
+			// Reject any attempt to rewrite LSB_FIRST and SBIO_INPUT_ONLY
 			if mask_pairs[index].0 == DDSCFRMask::LSB_FIRST || mask_pairs[index].0 == DDSCFRMask::SDIO_IN_ONLY {
 				continue;
 			}
@@ -177,7 +243,6 @@ where
 				_ => panic!("Invalid DDSCFRMask!"),
 			};
 		}
-		hprintln!("Modified array {:#X?}", data_array).unwrap();
 		self.set_all_configurations(data_array.clone())
 	}
 

src/lib.rs

@@ -6,10 +6,8 @@ use embedded_hal::{
 };
 
 use core::cell;
-use core::mem::size_of;
 
 use cortex_m;
-use cortex_m::asm::nop;
 use cortex_m_semihosting::hprintln;
 
 #[macro_use]

src/main.rs

@@ -10,13 +10,9 @@ use stm32h7xx_hal::hal::digital::v2::{
 use stm32h7xx_hal::{pac, prelude::*, spi};
 
 use cortex_m;
-use cortex_m::asm::nop;
 use cortex_m_rt::entry;
 use cortex_m_semihosting::hprintln;
 
-use core::ptr;
-use nb::block;
-
 use firmware;
 use firmware::{
 	CPLD,
@@ -102,7 +98,7 @@ fn main() -> ! {
 
 	let mut config = ConfigRegister::new(parts.spi1);
 	let mut att = Attenuator::new(parts.spi2);
-	let mut dds0 = DDS::new(parts.spi4);
+	let mut dds0 = DDS::new(parts.spi4, 25_000_000);
 
 	// Reset all DDS, set CLK_SEL to 0
 	config.set_configurations(&mut [
@@ -115,21 +111,9 @@ fn main() -> ! {
 		(CFGMask::IO_RST, 0),
 		(CFGMask::RST, 0),
 		(CFGMask::RF_SW, 13),
-		(CFGMask::DIV, 2)
+		(CFGMask::DIV, 3)
 	]).unwrap();
 
-	// dds0.write_register(0x00, &mut[
-	// 	0x00, 0x00, 0x00, 0x02
-	// ]).unwrap();
-
-	// dds0.write_register(0x01, &mut[
-	// 	0x01, 0x01, 0x00, 0x20
-	// ]).unwrap();
-
-	// dds0.write_register(0x02, &mut[
-	// 	0x05, 0x38, 0xC5, 0x28
-	// ]).unwrap();
-
 	dds0.init().unwrap();
 
 	dds0.set_configurations(&mut [
@@ -137,30 +121,17 @@ fn main() -> ! {
 		(DDSCFRMask::READ_EFFECTIVE_FTW,			1),
 		(DDSCFRMask::DIGITAL_RAMP_ENABLE,			0),
 		(DDSCFRMask::EN_AMP_SCALE_SINGLE_TONE_PRO,	1),
-		(DDSCFRMask::N,								0x14),
-		(DDSCFRMask::PLL_ENABLE,					1),
-		(DDSCFRMask::PFD_RESET,						1),
-		(DDSCFRMask::REFCLK_IN_DIV_BYPASS,			1),
-		(DDSCFRMask::I_CP,							7),
-		(DDSCFRMask::VCO_SEL,						5),
-		(DDSCFRMask::DRV0,							0),
 	]).unwrap();
 
-	hprintln!("{:#X?}", dds0.read_register(0x02, &mut[
-		0x00, 0x00, 0x00, 0x00
-	]).unwrap()).unwrap();
-
-	dds0.set_configurations(&mut [
-		(DDSCFRMask::PFD_RESET,						0),
-	]).unwrap();
+	dds0.enable_pll(1_150_000_000).unwrap();
 
 	hprintln!("{:#X?}", dds0.read_register(0x02, &mut[
 		0x00, 0x00, 0x00, 0x00
 	]).unwrap()).unwrap();
 
 	// Calculate FTW
-	let f_out = 8_008_135;
-	let f_sclk = 100_000_000 / 2 * 20;
+	let f_out = 10_000_000;
+	let f_sclk = 1_150_000_000;
 	let resolution :u64 = 1 << 32;
 	let ftw = (resolution * f_out / f_sclk) as u32;
 
@@ -177,6 +148,7 @@ fn main() -> ! {
 	profile[7] = ((ftw >> 0 ) & 0xFF) as u8;
 
 	dds0.write_register(0x0E, &mut profile).unwrap();
+	hprintln!("{:#X?}", dds0.read_register(0x0E, &mut profile).unwrap()).unwrap();
 
 	// Attenuator
 	att.set_attenuation([