diff --git a/.vscode/launch.json b/.vscode/launch.json
index 56464e766e2e4931a50f363d770cbd759d4d23f7..09516bde169f299a9bf8dff4dcbeea85cadb641e 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -382,6 +382,7 @@
"request": "launch",
"servertype": "openocd",
"name": "bare6 (debug) 64Mhz",
+ "preLaunchTask": "cargo build --example bare6 --features stm32f4",
"executable": "./target/thumbv7em-none-eabihf/debug/examples/bare6",
"configFiles": [
"interface/stlink.cfg",
@@ -410,6 +411,7 @@
"request": "launch",
"servertype": "openocd",
"name": "bare6 (debug) 84Mhz",
+ "preLaunchTask": "cargo build --example bare6 --features stm32f4",
"executable": "./target/thumbv7em-none-eabihf/debug/examples/bare6",
"configFiles": [
"interface/stlink.cfg",
diff --git a/examples/bare6.rs b/examples/bare6.rs
index f2d6f75158d117e519b7b7bc7de2c910da17065d..32eab268ca1d6c0114d910da5c73bee8844c11f0 100644
--- a/examples/bare6.rs
+++ b/examples/bare6.rs
@@ -27,40 +27,36 @@
extern crate panic_halt;
use cortex_m::{iprint, iprintln, peripheral::itm::Stim, peripheral::syst::SystClkSource};
-use cortex_m_rt::entry;
+use cortex_m_rt::{entry, exception};
-// use cortex_m_semihosting::hprintln;
use stm32f4::stm32f411;
-use stm32f411::{DWT, GPIOA, NVIC, /* interrupt, Peripherals, Interrupt, ITM, */ RCC};
+use stm32f411::{interrupt, Interrupt, DWT, GPIOA, GPIOC, ITM, NVIC, RCC, SYST};
+
#[entry]
fn main() -> ! {
let p = stm32f411::Peripherals::take().unwrap();
let mut c = stm32f411::CorePeripherals::take().unwrap();
- //p.GPIOA.odr.write(|w| w.bits(1));
-
- //let stim = &mut p.
-
let stim = &mut c.ITM.stim[0];
iprintln!(stim, "Hello, bare6!");
- // // let dwt = unsafe { &mut *DWT.get() }; // get the reference to DWD in memory
- // // let rcc = unsafe { &mut *RCC.get() }; // get the reference to RCC in memory
- // // let gpioa = unsafe { &mut *GPIOA.get() }; // get the reference to GPIOA in memory
- // // let gpioc = unsafe { &mut *GPIOC.get() }; // get the reference to GPIOC in memory
- // // let flash = unsafe { &mut *FLASH.get() }; // get the reference to FLASH in memory
+ c.DWT.enable_cycle_counter();
+ unsafe {
+ c.DWT.cyccnt.write(0);
+ }
+ let t = DWT::get_cycle_count();
+ iprintln!(stim, "{}", t);
- // p.DWT.enable_cycle_counter();
- // // clock_out(rcc, gpioc);
- // // //clock::set_84_mhz(rcc, flash);
- idle(stim, c.DWT, p.RCC, p.GPIOA);
+ clock_out(&p.RCC, &p.GPIOC);
+ // clock::set_84_mhz(rcc, flash);
+ idle(stim, p.RCC, p.GPIOA);
loop {}
}
// // user application
-fn idle(stim: &mut Stim, dwt: DWT, rcc: RCC, gpioa: GPIOA) {
+fn idle(stim: &mut Stim, rcc: RCC, gpioa: GPIOA) {
iprintln!(stim, "idle");
// power on GPIOA, RM0368 6.3.11
@@ -69,156 +65,170 @@ fn idle(stim: &mut Stim, dwt: DWT, rcc: RCC, gpioa: GPIOA) {
// configure PA5 as output, RM0368 8.4.1
gpioa.moder.modify(|_, w| w.moder5().bits(1));
- // at 16 Mhz, 8000_0000 cycles = period 0.5s
- // at 64 Mhz, 8000_0000 cycles = period 0.125s
- let cycles = 8000_0000;
+ // at 16 Mhz, 8_000_000 cycles = period 0.5s
+ // at 64 Mhz, 4*8_000_000 cycles = period 0.55s
+ // let cycles = 8_000_000;
+ let cycles = 4*8_000_000;
+
loop {
- // ipln!("led on");
+ iprintln!(stim, "on {}", DWT::get_cycle_count());
// set PA5 high, RM0368 8.4.7
gpioa.bsrr.write(|w| w.bs5().set_bit());
- wait_cycles(&dwt, cycles);
+ wait_cycles(cycles);
- // ipln!("led off");
+
+ iprintln!(stim, "off {}", DWT::get_cycle_count());
// set PA5 low, RM0368 8.4.7
gpioa.bsrr.write(|w| w.br5().set_bit());
- wait_cycles(&dwt, cycles);
+ wait_cycles(cycles);
}
}
// uses the DWT.CYCNT
// doc: ARM trm_100166_0001_00_en.pdf, chapter 9.2
// we use the `cortex-m` abstraction, as re-exported by the stm32f40x
-fn wait_cycles(dwt: &DWT, nr_cycles: u32) {
- let t = dwt.cyccnt.read().wrapping_add(nr_cycles);
- while (dwt.cyccnt.read().wrapping_sub(t) as i32) < 0 {}
+fn wait_cycles(nr_cycles: u32) {
+ let t = DWT::get_cycle_count().wrapping_add(nr_cycles);
+ while (DWT::get_cycle_count().wrapping_sub(t) as i32) < 0 {}
}
// see the Reference Manual RM0368 (www.st.com/resource/en/reference_manual/dm00096844.pdf)
// rcc, chapter 6
// gpio, chapter 8
-// fn clock_out(rcc: &mut RCC, gpioc: &mut GPIOC) {
-// // output MCO2 to pin PC9
+fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
+ // output MCO2 to pin PC9
-// // mco2 : SYSCLK = 0b00
-// // mcopre : divide by 4 = 0b110
-// rcc.cfgr
-// .modify(|_, w| unsafe { w.mco2().bits(0b00).mco2pre().bits(0b110) });
+ // mco2 : SYSCLK = 0b00
+ // mcopre : divide by 4 = 0b110
+ rcc.cfgr
+ .modify(|_, w| unsafe { w.mco2().bits(0b00).mco2pre().bits(0b110) });
-// // power on GPIOC, RM0368 6.3.11
-// rcc.ahb1enr.modify(|_, w| w.gpiocen().set_bit());
+ // power on GPIOC, RM0368 6.3.11
+ rcc.ahb1enr.modify(|_, w| w.gpiocen().set_bit());
-// // MCO_2 alternate function AF0, STM32F401xD STM32F401xE data sheet
-// // table 9
-// // AF0, gpioc reset value = AF0
+ // MCO_2 alternate function AF0, STM32F401xD STM32F401xE data sheet
+ // table 9
+ // AF0, gpioc reset value = AF0
-// // configure PC9 as alternate function 0b10, RM0368 6.2.10
-// gpioc.moder.modify(|_, w| unsafe { w.moder9().bits(0b10) });
+ // configure PC9 as alternate function 0b10, RM0368 6.2.10
+ gpioc.moder.modify(|_, w| w.moder9().bits(0b10) );
-// // otyper reset state push/pull, in reset state (don't need to change)
+ // otyper reset state push/pull, in reset state (don't need to change)
-// // ospeedr 0b11 = high speed
-// gpioc
-// .ospeedr
-// .modify(|_, w| unsafe { w.ospeedr9().bits(0b11) });
-// }
+ // ospeedr 0b11 = high speed
+ gpioc
+ .ospeedr
+ .modify(|_, w| w.ospeedr9().bits(0b11) );
+}
// 1. Compile and run the example, in 16Mhz
// The processor SYSCLK defaults to HCI 16Mhz
// (this is what you get after a `monitor reset halt`).
//
-// confirm that your ITM dump traces the init, idle and led on/off
-// make sure your TPIU is set to a system clock at 16Mhz
+// Confirm that your ITM dump traces the init, idle and led on/off.
+// Make sure your TPIU is set to a system clock at 16Mhz
+//
+// What is the frequency of blinking?
+//
+// ** your answer here **
+//
+// commit your answers (bare6_1)
+//
+// 2. Now connect an oscilloscope to PC9, which is set to
+// output the MCO2.
+//
+// What is the frequency of MCO2 read by the oscilloscope?
+//
+// ** your answer here **
+//
+// Compute the value of SYSCLK based on the oscilloscope reading
+//
+// ** your answer here **
+//
+// What is the peak to peak reading of the signal?
+//
+// ** your answer here **
+//
+// Make a folder called "pictures" in your git project.
+// Make a screen dump or photo of the oscilloscope output.
+// Save the the picture as "bare_6_16mhz_high_speed".
+//
+// commit your answaaasers (bare6_2)
+//
+// 3. Now run the example in 64Mz
+// You can do that by issuing a `monitor reset init`
+// which reprograms SYSCLK to 4*HCI.
+//
//
-// you may use either ITM tracing using ITM dump or internally in
-// vscode using the new "cortex debug" plugin
+// Confirm that your ITM dump traces the init, idle and led on/off
+// (make sure your TPIU is set to a system clock at 64Mhz)
//
-// what is the frequency of blinking
-// ** your answer here **
+// Uncommnet: `let cycles = 4 * 8_000_000;
+//`
+// What is the frequency of blinking?
//
-// commit your answers (bare6_1)
+// ** your answer here **
//
-// 2. now connect an oscilloscope to PC9, which is set to
-// output the MCO2
+// commit your answers (bare6_3)
//
-// what is the frequency of MCO2 read by the oscilloscope
-// ** your answer here **
+// 4. Repeat experiment 2
//
-// compute the value of SYSCLK based on the oscilloscope reading
-// ** your answer here **
+// What is the frequency of MCO2 read by the oscilloscope?
//
-// what is the peak to peak reading of the signal
-// ** your answer here **
+// ** your answer here **
//
-// make a folder called "pictures" in your git project
-// make a screen dump or photo of the oscilloscope output
-// save the the picture as "bare_6_16mhz_high_speed"
+// Compute the value of SYSCLK based on the oscilloscope reading.
//
-// commit your answaaasers (bare6_2)
+// ** your answer here **
//
-// 3. now run the example in 64Mz
-// you can do that by issuing a `monitor reset init`
-// which reprograms SYSCLK to 4*HCI
-// (make sure you have the latest openocd v 0.10)
+// What is the peak to peak reading of the signal?
//
-// confirm that your ITM dump traces the init, idle and led on/off
-// (make sure your TPIU is set to a system clock at 64Mhz)
+// ** your answer here **
//
-// what is the frequency of blinking
-// ** your answer here **
+// Make a screen dump or photo of the oscilloscope output.
+// Save the the picture as "bare_6_64mhz_high_speed".
//
-// commit your answers (bare6_3)
+// commit your answers (bare6_4)
//
-// 4. repeat the experiment 2
-// what is the frequency of MCO2 read by the oscilloscope
-// ** your answer here **
+// 5. Now we will put the MCU in 84MHz using the function
+// clock::set_84_mhz(rcc, flash);
//
-// compute the value of SYSCLK based on the oscilloscope reading
-// ** your answer here **
-// what is the peak to peak reading of the signal
+// This function is part of the `f4` support crate (by Johonnes Sjölund)
+// besides `rcc` (for clocking) it takes `flash` as a parameter to set
+// up correct latency (wait states) for the flash memory (where our
+// program typically resides). This is required since the flash cannot
+// operate at the full 84MHz, so the MCU has to wait for the memory.
//
-// ** your answer here **
+// Repeat the experiment 2.
//
-// make a screen dump or photo of the oscilloscope output
-// save the the picture as "bare_6_64mhz_high_speed"
+// What is the frequency of MCO2 read by the oscilloscope.
//
-// commit your answers (bare6_4)
+// ** your answer here **
//
-// 5. now we will put the MCU in 84MHz using the function
-// clock::set_84_mhz(rcc, flash);
+// Compute the value of SYSCLK based on the oscilloscope reading.
//
-// this function is part of the `f4` support crate (by Johonnes Sjölund)
-// besides `rcc` (for clocking) it takes `flash` as a parameter to set
-// up correct latency (wait states) for the flash memory (where our
-// program typically resides). This is required since the flash cannot
-// operate at the full 84MHz, so the MCU has to wait for the memory.
+// ** your answer here **
//
-// repeat the experiment 2.
-// what is the frequency of MCO2 read by the oscilloscope
-// ** your answer here **
+// What is the peak to peak reading of the signal.
//
-// compute the value of SYSCLK based on the oscilloscope reading
-// ** your answer here **
-// what is the peak to peak reading of the signal
+// ** your answer here **
//
-// ** your answer here **
+// Make a screen dump or photo of the oscilloscope output.
+// Save the the picture as "bare_6_84mhz_high_speed"
//
-// make a screen dump or photo of the oscilloscope output
-// save the the picture as "bare_6_84mhz_high_speed"
+// commit your answers (bare6_5)
//
-// commit your answers (bare6_5)
+// 6. Now reprogram the PC9 to be "Low Speed", and re-run at 84Mz.
//
-// 6. now reprogram the PC9 to be "Low Speed", and re-run at 84Mz
+// Did the frequency change in comparison to assignment 5?
//
-// did the frequency change in comparison to assignment 5.
-// ** your answer here **
+// ** your answer here **
//
-// what is the peak to peak reading of the signal
-// ** your answer here **
+// What is the peak to peak reading of the signal (and why did it change)?
//
-// why does it differ?
-// ** your answer here **
+// ** your answer here **
//
-// make a screen dump or photo of the oscilloscope output
-// save the the picture as "bare_6_84mhz_low_speed"
+// Make a screen dump or photo of the oscilloscope output.
+// Save the the picture as "bare_6_84mhz_low_speed".
//
-// commit your answers (bare6_6)
+// commit your answers (bare6_6)