standby 3uA

.vscode/launch.json

@@ -82,6 +82,31 @@
             },
             "cwd": "${workspaceRoot}"
         },
+        {
+            "type": "cortex-debug",
+            "request": "launch",
+            "servertype": "openocd",
+            "name": "standby (release)",
+            "executable": "./target/thumbv7em-none-eabihf/release/examples/standby",
+            "configFiles": [
+                "interface/stlink.cfg",
+                "target/stm32f4x.cfg"
+            ],
+            "swoConfig": {
+                "enabled": true,
+                "cpuFrequency": 8000000,
+                "swoFrequency": 2000000, // you may try 1000000 if not working
+                "source": "probe",
+                "decoders": [
+                    {
+                        "type": "console",
+                        "label": "Name",
+                        "port": 0
+                    }
+                ]
+            },
+            "cwd": "${workspaceRoot}"
+        },
         {
             "type": "cortex-debug",
             "request": "launch",

examples/standby.rs

@@ -34,16 +34,54 @@ extern crate stm32f40x;
 extern crate cortex_m_rt as rt;
 
 // makes `panic!` print messages to the host stderr using semihosting
-extern crate panic_semihosting;
-
+// extern crate panic_semihosting;
+extern crate panic_abort;
 use cortex_m::asm;
 use rt::ExceptionFrame;
 
+use cortex_m::peripheral::{Peripherals, SCB};
+use stm32f40x::DBG;
+
 // the program entry point is ...
 entry!(main);
 
 // ... this never ending function
 fn main() -> ! {
+    // let scb = p.core.SCB;
+    asm::bkpt();
+
+    let mut p = Peripherals::take().unwrap();
+    p.SCB.set_sleepdeep();
+
+    let mut r = stm32f40x::Peripherals::take().unwrap();
+
+    let v = r.DBG.dbgmcu_cr.read();
+    r.DBG.dbgmcu_cr.modify(|_, w| {
+        w.dbg_sleep()
+            .clear_bit()
+            .dbg_stop()
+            .clear_bit()
+            .dbg_standby()
+            .clear_bit()
+    });
+
+    let v1 = r.DBG.dbgmcu_cr.read();
+    asm::bkpt();
+
+    // enable pwr
+    r.RCC.apb1enr.modify(|_, w| w.pwren().set_bit());
+
+    // standby mode
+    r.PWR
+        .cr
+        .modify(|_, w| w.pdds().set_bit().cwuf().clear_bit());
+    // // pwr.cr.modify(|_, w| w.lpds().clear_bit()); // regulator in normal mode
+    // pwr.cr.modify(|_, w| w.lpds().set_bit()); // regulator in low power mode
+    // exti.pr.write(|w| unsafe { w.bits(0) }); // clear pending register
+    // pwr.csr.modify(|_, w| w.ewup().set_bit()); // clear pending wake up
+
+    asm::bkpt();
+
     loop {
         asm::wfi();
         asm::bkpt();