bare5_

examples/bare5.rs

@@ -57,12 +57,20 @@ mod stm32f40x {
     // width  (field width)
     // value  (new value that the field should take)
     //
-    // impl VolatileCell<u32> {
-    //     #[inline(always)]
-    //     pub fn modify(&self, offset: u8, width: u8, value: u32) {
-    //         // your code here
-    //     }
-    // }
+     impl VolatileCell<u32> {
+         #[inline(always)]
+         pub fn modify(&self, offset: u8, width: u8, value: u32) {
+             // your code here
+             let mask:u32 = (1<<width)-1 ;
+             let mut valueOfMask: u32 = 0;
+             if (width > 0 ){
+                valueOfMask = mask & value;
+             }
+             let reader = self.read() & !(mask << offset);
+             self.write(reader | (value & valueOfMask) << offset);
+
+         }
+     }
 
     #[repr(C)]
     #[allow(non_snake_case)]
@@ -141,27 +149,27 @@ fn wait(i: u32) {
 }
 
 // simple test of Your `modify`
-//fn test() {
-// let t:VolatileCell<u32> = unsafe {  core::mem::uninitialized() };
-// t.write(0);
-// assert!(t.read() == 0);
-// t.modify(3, 3, 0b10101);
+fn test() {
+ let t:VolatileCell<u32> = unsafe {  core::mem::uninitialized() };
+ t.write(0);
+ assert!(t.read() == 0);
+ t.modify(3, 3, 0b10101);
 // //
 // //     10101
 // //    ..0111000
 // //    ---------
 // //    000101000
-// assert!(t.read() == 0b101 << 3);
-// t.modify(4, 3, 0b10001);
+ assert!(t.read() == 0b101 << 3);
+ t.modify(4, 3, 0b10001);
 // //    000101000
 // //      111
 // //      001
 // //    000011000
-// assert!(t.read() == 0b011 << 3);
+ assert!(t.read() == 0b011 << 3);
 
 // if << is used, your code will panic in dev (debug), but not in release mode
-// t.modify(32, 3, 1);
-//}
+ t.modify(32, 3, 1);
+}
 
 // system startup, can be hidden from the user
 #[entry]
@@ -191,7 +199,7 @@ fn idle(rcc: &mut RCC, gpioa: &mut GPIOA) {
         //gpioa.BSRRH.write(1 << 5); // set bit, output hight (turn on led)
                                    // alternatively to set the bit high we can
                                    // read the value, or with PA5 (bit 5) and write back
-        gpioa.ODR.write(gpioa.ODR.read() | (1 << 5));
+        gpioa.ODR.modify(5, 1, 1);
 
         wait(10_000);
 
@@ -199,7 +207,7 @@ fn idle(rcc: &mut RCC, gpioa: &mut GPIOA) {
         //gpioa.BSRRL.write(1 << 5); // clear bit, output low (turn off led)
                                    // alternatively to clear the bit we can
                                    // read the value, mask out PA5 (bit 5) and write back
-        gpioa.ODR.write(gpioa.ODR.read() & !(1 << 5));
+        gpioa.ODR.modify(5, 1, 0);
         wait(10_000);
     }
 }