scpi: implement rst

examples/ethernet.rs

@@ -131,7 +131,7 @@ fn main() -> ! {
         .sys_ck(200.mhz())
         .hclk(200.mhz())
         .pll1_r_ck(100.mhz())   // for TRACECK
-        .pll1_q_ck(48.mhz())
+        .pll1_q_ck(48.mhz())    // for SPI
         .freeze(vos, &dp.SYSCFG);
 
     // Get the delay provider.

src/dds.rs

@@ -144,33 +144,36 @@ where
 		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!");
+			// panic!("Invalid divider value for PLL!");
+			return Err(Error::DDSCLKError);
 		}
-		// 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
-		};
+		// // 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
+		// };
+		let vco = self.get_VCO_no(f_sys_clk, divider as u8)?;
+
 		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),
+			(DDSCFRMask::VCO_SEL, vco.into()),
 			// Reset PLL lock before re-enabling it
 			(DDSCFRMask::PFD_RESET, 1),
 		])?;
@@ -182,9 +185,76 @@ where
 	}
 
 	// Change external clock source (ref_clk)
-	pub fn set_ref_clk_frequency(&mut self, f_ref_clk: u64) {
+	pub fn set_ref_clk_frequency(&mut self, f_ref_clk: u64) -> Result<(), Error<E>> {
 		self.f_ref_clk = f_ref_clk;
 		// TODO: Examine clock tree and update f_sys_clk
+		let mut configuration_queries = [
+			// Acquire PLL status
+			(DDSCFRMask::PLL_ENABLE, 0),
+			// Acquire N-divider, to adjust VCO if necessary
+			(DDSCFRMask::N, 0),
+			// Acquire REF_CLK divider bypass
+			(DDSCFRMask::REFCLK_IN_DIV_BYPASS, 0)
+		];
+
+		self.get_configurations(&mut configuration_queries)?;
+		if configuration_queries[0].1 == 1 {
+			// Recalculate sys_clk
+			let divider :u64 = configuration_queries[1].1.into();
+			let f_sys_clk = self.f_ref_clk * divider;
+			// Adjust VCO
+			match self.get_VCO_no(f_sys_clk, divider as u8) {
+				Ok(vco_no) => {
+					self.set_configurations(&mut [
+						// Update VCO selection
+						(DDSCFRMask::VCO_SEL, vco_no.into()),
+						// Reset PLL lock before re-enabling it
+						(DDSCFRMask::PFD_RESET, 1),
+					])?;
+					self.set_configurations(&mut [
+						(DDSCFRMask::PFD_RESET, 0),
+					])?;
+					// Update f_sys_clk from recalculation
+					self.f_sys_clk = f_sys_clk;
+					Ok(())
+				},
+				Err(_) => {
+					// Forcibly turn off PLL, enable default clk tree (divide by 2)
+					self.enable_divided_ref_clk()
+				}
+			}
+		}
+		else if configuration_queries[2].1 == 0 {
+			self.f_sys_clk = self.f_ref_clk / 2;
+			Ok(())
+		}
+		else {
+			self.f_sys_clk = self.f_ref_clk;
+			Ok(())
+		}
+	}
+
+	fn get_VCO_no(&mut self, f_sys_clk: u64, divider: u8) -> Result<u8, Error<E>> {
+		// Select a VCO
+		if divider == 1 {
+			Ok(6)	// Bypass PLL if no frequency division needed
+		} else if f_sys_clk > 1_150_000_000 {
+			Err(Error::DDSCLKError)
+		} else if f_sys_clk > 820_000_000 {
+			Ok(5)
+		} else if f_sys_clk > 700_000_000 {
+			Ok(4)
+		} else if f_sys_clk > 600_000_000 {
+			Ok(3)
+		} else if f_sys_clk > 500_000_000 {
+			Ok(2)
+		} else if f_sys_clk > 420_000_000 {
+			Ok(1)
+		} else if f_sys_clk > 370_000_000 {
+			Ok(0)
+		} else {
+			Ok(7)	// Bypass PLL if f_sys_clk is too low
+		}
 	}
 
 	/*

src/lib.rs

@@ -26,6 +26,7 @@ use crate::cpld::DoOnGetRefMutData;
 
 pub mod config_register;
 use crate::config_register::ConfigRegister;
+use crate::config_register::CFGMask;
 
 pub mod attenuator;
 use crate::attenuator::Attenuator;
@@ -46,6 +47,8 @@ pub enum Error<E> {
 	AttenuatorError,
 	IOUpdateError,
 	DDSError,
+	ConfigRegisterError,
+	DDSCLKError,
 }
 
 /*
@@ -78,6 +81,46 @@ where
 			],
 		}
 	}
+
+	/*
+	 *  Reset method. To be invoked by initialization and manual reset.
+	 *  Only Urukul struct provides reset method.
+	 *  DDS reset is controlled by Urukul (RST).
+	 *  Attenuators only have shift register reset, which does not affect its data
+	 *  CPLD only has a "all-zero" default state.
+	 */
+	pub fn reset(&mut self) -> Result<(), Error<E>> {
+		// Reset DDS and attenuators
+		self.config_register.set_configurations(&mut [
+			(CFGMask::RST, 1),
+			(CFGMask::IO_RST, 1),
+			(CFGMask::IO_UPDATE, 0)
+		])?;
+		// Set 0 to all fields on configuration register.
+		self.config_register.set_configurations(&mut [
+			(CFGMask::RF_SW, 		0),
+			(CFGMask::LED, 			0),
+			(CFGMask::PROFILE, 		0),
+			(CFGMask::IO_UPDATE, 	0),
+			(CFGMask::MASK_NU, 		0),
+			(CFGMask::CLK_SEL0, 	0),
+			(CFGMask::SYNC_SEL, 	0),
+			(CFGMask::RST, 			0),
+			(CFGMask::IO_RST, 		0),
+			(CFGMask::CLK_SEL1, 	0),
+			(CFGMask::DIV, 			0),
+		])?;
+		// Init all DDS chips. Configure SDIO as input only.
+		for chip_no in 0..4 {
+			self.dds[chip_no].init()?;
+		}
+
+		// Clock tree reset. CPLD divides clock frequency by 4 by default.
+		for chip_no in 0..4 {
+			self.dds[chip_no].set_ref_clk_frequency(25_000_000);
+		}
+		Ok(())
+	}
 }
 
 // /*

src/scpi.rs

@@ -28,6 +28,8 @@ use scpi::{
     scpi_tree,
 };
 
+use embedded_hal::blocking::spi::Transfer;
+
 use crate::Urukul;
 
 // pub struct MyDevice;
@@ -50,13 +52,21 @@ impl Command for HelloWorldCommand {
  *  Implement "Device" trait from SCPI
  *  TODO: Implement mandatory commands
  */
- impl<SPI> Device for Urukul<SPI> {
+impl<SPI, E> Device for Urukul<SPI> 
+where
+    SPI: Transfer<u8, Error = E>
+{
     fn cls(&mut self) -> Result<()> {
         Ok(())
     }
 
     fn rst(&mut self) -> Result<()> {
-        Ok(())
+        match self.reset() {
+            Ok(_) => Ok(()),
+            Err(_) => Err(Error::new(
+                ErrorCode::HardwareError
+            ))
+        }
     }
 }