Corrected my answers in rtt_timing

examples/rtt_timing.rs

@@ -55,12 +55,12 @@ fn timed_loop() -> (u32, u32) {
 // > cargo run --example rtt_timing
 //
 // [Your answer here]
-// 2987
+// 4790152 cycles
 //
 // A.2) How many cycles per iteration?
 //
 // [Your answer here]
-// 4790152
+// 479.0152 cycles
 //
 // A.3) Why do we need a wrapping subtraction?
 //
@@ -75,17 +75,17 @@ fn timed_loop() -> (u32, u32) {
 // start 30305915, end 30375916, diff 70001
 //
 // [Your answer here]
-// 30305915
+// 70001 cycles
 //
 // B.2) How many cycles per iteration?
 //
 // [Your answer here]
-// 70001
+// 7.0001 cycles
 //
 // What is the speedup (A/B)?
 //
 // [Your answer here]
-// 4790152 / 70001 = 68.4297652891
+// 479.0152 / 7.0001 = 68.4297652891
 // 
 //
 // Why do you think it differs that much?
@@ -124,17 +124,17 @@ fn timed_loop() -> (u32, u32) {
 // start 1356808538, end 1356848539, diff 40001
 //
 // [Your answer here]
-// 1356808538
+// 40001 cycles
 //
 // C.2) How many cycles per iteration?
 //
 // [Your answer here]
-// 40001
+// 4.0001 cycles
 //
 // What is the speedup (A/C)?
 //
 // [Your answer here]
-// 4790152 / 40001 = 119.75080623
+// 479.0152 / 4.0001 = 119.75080623
 //
 // ------------------------------------------------------------------------
 // D) Now lets have a closer look at the generated assembly.
@@ -223,7 +223,7 @@ fn timed_loop() -> (u32, u32) {
 // https://developer.arm.com/documentation/ddi0439/b/Data-Watchpoint-and-Trace-Unit/DWT-Programmers-Model
 //
 // [Your answer here]
-// No, there is no function call. The two following line loads in the loaction of the cycle count,
+// No, there is no function call. The two following line loads in the location of the cycle count,
 // which is always updated. Thus r1 holds the location of the cycle counter.
 // 0x08000232 <+0>:     movw    r1, #4100       ; 0x1004
 // 0x0800023a <+8>:     movt    r1, #57344      ; 0xe000
@@ -300,7 +300,7 @@ fn timed_loop() -> (u32, u32) {
 // By how much does the cycle counter increase for each iteration?
 //
 // [Your answer here]
-// 4
+// 4 cycles
 //
 // ------------------------------------------------------------------------
 // F) Reseting the cycle counter
@@ -337,7 +337,7 @@ fn timed_loop() -> (u32, u32) {
 // (when hitting the `timed_loop` breakpoint)?
 //
 // [Your answer here]
-// 0x00000009
+// 0x00000009 = 9 cycles
 //
 // ------------------------------------------------------------------------
 // G) Finally some statics