Fix typos

Author: GorgonMeducer

README.md

@@ -20,7 +20,7 @@ A dedicated performance counter for Cortex-M Systick. It shares the SysTick with
   - Easy to port to a different architecture with a porting template
 
 - **Provide Free Services**
-  - Do **NOT** interfer with existing SysTick based applications
+  - Do **NOT** interfere with existing SysTick-based applications
 - **Support most of the arm compilers**
   - Arm Compiler 5 (armcc), Arm Compiler 6 (armclang)
   - arm gcc
@@ -30,7 +30,7 @@ A dedicated performance counter for Cortex-M Systick. It shares the SysTick with
   - **Drag-and-Drop deployment for Arm Compiler 5 and Arm Compiler 6.**
   - **CMSIS-Pack is available**
   - **RT-Thread package is avaialble**
-- **Time based services**
+- **Time-based services**
   - `delay_us()` and `delay_ms()` with **64bit return value**.
   - Provides Timestamp services via `get_system_ticks()`, `get_system_us` and `get_system_ms()`.
 - **Support both RTOS and bare-metal environments**
@@ -39,12 +39,12 @@ A dedicated performance counter for Cortex-M Systick. It shares the SysTick with
   - Support stack-overflow detection in RTOS environment via `perfc_check_task_stack_canary_safe()`
 - **Utilities for C language enhancement**
   - Macros to detect compilers, e.g. `__IS_COMPILER_ARM_COMPILER_6__`, `__IS_COMPILER_LLVM__` etc.
-  - Macro to create atomicity for specified code block, i.e. `__IRQ_SAFE{...}`
+  - Macro to create atomicity for a specified code block, i.e. `__IRQ_SAFE{...}`.
   - Helper macros for C language extension:
     - VB like `with()`
     - `foreach()`, dimof(), `CONNECT()`
     - C# like `using()`
-    - simple overload feature of OOPC made out of ANSI-C99, `__PLOOC_VA_NUM_ARGS()`
+    - simple overload feature of OOPC made out of ANSI-C99, `__PLOOC_VA_NUM_ARGS()`.
     - **[new]** add macros for PT
     - ...
   - A dedicated macro `__perfc_sync_barrier__()` for code barrier. 
@@ -53,9 +53,9 @@ A dedicated performance counter for Cortex-M Systick. It shares the SysTick with
 
 ## 1. How To Use
 
-### 1.1 Measure CPU cycles for specified code segment
+### 1.1 Measure CPU cycles for a specified code segment
 
-You can measure specified code segment with a macro helper `__cycleof__()`, it is a wrapper of `get_system_ticks()`.
+You can measure a specified code segment with a macro helper `__cycleof__()`, a wrapper of `get_system_ticks()`.
 
 **Syntax:**
 
@@ -66,7 +66,7 @@ __cycleof__(<Description String for the target>, [User Code, see ref 1]) {
 }
 ```
 
-Here, [**ref 1**] is a small user code to read the measurement result via a local variable `__cycle_count__` . This User Code is optional. If you don't put anything here, the measured result will be shown with a `__perf_counter_printf__`. 
+Here, [**ref 1**] is a small user code to read the measurement result via a local variable `__cycle_count__`. This User Code is optional. If you don't put anything here, the measured result will be shown with a `__perf_counter_printf__`. 
 
 #### **Example 1:** Simple measurement with printf
 
@@ -78,7 +78,7 @@ Here, [**ref 1**] is a small user code to read the measurement result via a loca
     }
 ```
 
-You will see the measured result in console:
+You will see the measured result in the console:
 
 ![image-20220509004258020](./documents/pictures/__cycleof___output_simple) 
 
@@ -87,18 +87,18 @@ You will see the measured result in console:
 #### **Example 2:** Read measured result via `__cycle_counter__`
 
 ```c
-    int32_t iCycleResult = 0;
+    int64_t lCycleResult = 0;
 
     /* measure cycles and store it in a dedicated variable without printf */
     __cycleof__("delay_us(1000ul)", 
         /* insert code to __cycleof__ body, "{}" can be omitted  */
         {
-            iCycleResult = __cycle_count__;   /*< "__cycle_count__" stores the result */
+            lCycleResult = __cycle_count__;   /*< "__cycle_count__" stores the result */
         }) {
         delay_us(1000ul);
     }
 
-    printf("\r\n delay_us(1000ul) takes %d cycles\r\n", (int)iCycleResult);
+    printf("\r\n delay_us(1000ul) takes %lld cycles\r\n", lCycleResult);
 ```
 
 The result is read out from `__cycle_count__`and used in other place:
@@ -109,12 +109,12 @@ The result is read out from `__cycle_count__`and used in other place:
 
 #### 1.2.1 CPU Usage
 
-For both bare-metal and OS environment, you can measure the CPU Usage with macro `__cpu_usage__()` for a given code segment as long as it is executed repeatedly. 
+For both bare-metal and OS environments, you can measure the CPU Usage with macro `__cpu_usage__()` for a given code segment as long as it is executed repeatedly. 
 
 **Syntax**
 
 ```c
-__cycleof__(<Iteration Count before getting an average result>, [User Code, see ref 1]) {
+__cpu_usage__(<Iteration Count before getting an average result>, [User Code, see ref 1]) {
     //! target code segment of measurement
     ...
 }
@@ -177,7 +177,7 @@ __cpu_perf__(<Description String for the target>, [User Code, see ref 1]) {
 }
 ```
 
-Here, [**ref 1**] is a small user code to read the measurement result via a local **struct** variable `__PERF_INFO__` . This User Code is optional. If you don't put anything here, the measured result will be shown with a `__perf_counter_printf__`. The prototype of the `__PERF_INFO__` is shown below:
+Here, [**ref 1**] is a small user code to read the measurement result via a local **struct** variable `__PERF_INFO__`. This User Code is optional. If you don't put anything here, the measured result will be shown with a `__perf_counter_printf__`. The prototype of the `__PERF_INFO__` is shown below:
 
 ```c
 struct {                                                                
@@ -192,7 +192,7 @@ struct {
 } __PERF_INFO__;
 ```
 
-For example, when insert user code, you can read CPI from `__PERF_INFO__.fCPI`.
+For example, when inserting user code, you can read CPI from `__PERF_INFO__.fCPI`.
 
 **Example 1: measure the Coremark**
 
@@ -223,13 +223,13 @@ The result might look like the following:
 
 ### 1.3 Timestamp
 
-You can get the system timestamp (since the initialization of perf_counter service) via function `get_system_ticks()` and `get_system_ms()`. 
+You can get the system timestamp (since the initialization of perf_counter service) via the functions `get_system_ticks()` and `get_system_ms()`. 
 
 **NOTE**: The `get_system_ms()` is **NOT** a wrapper of the function `get_system_ticks()`. 
 
 
 
-There are various way to take advantage of those functions. 
+There are various ways to take advantage of those functions. 
 
 #### Example 3: Use `get_system_ms()` as random seed
 
@@ -244,7 +244,7 @@ int main (void)
    
    n = 5;
    
-   /* Intializes random number generator */
+   /* Initialize random number generator */
    srand((unsigned) get_system_ticks());
 
    /* Print 5 random numbers from 0 to 1024 */
@@ -270,7 +270,7 @@ int main (void)
     } while(0);
 ```
 
-This example shows how to use the delta value of `get_system_ticks()` to measure the CPU cycles used by specified code segment. In fact, the `__cycleof__()` is implemented in the same way:
+This example shows how to use the delta value of `get_system_ticks()` to measure the CPU cycles used by a specified code segment. In fact, the `__cycleof__()` is implemented in the same way:
 
 ```c
 #define __cycleof__(__STR, ...)                                                 \
@@ -294,7 +294,7 @@ This example shows how to use the delta value of `get_system_ticks()` to measure
 
 ### 1.4 Timer Services
 
-perf_counter provides the basic timer services for delaying a given period of time and polling-for-timeout. For example:
+perf_counter provides the basic timer services for delaying a given period and polling-for-timeout. For example:
 
 ```c
 delay_ms(1000);   /* block the program for 1000ms */
@@ -315,9 +315,9 @@ while(1) {
 
 ### 1.5 Work with EventRecorder in MDK
 
-If you are using EventRecorder in MDK, once you deployed the `perf_counter`, it will provide the timer service for EventRecorder by implenting the following functions: `EventRecorderTimerSetup()`, `EventRecorderTimerGetFreq()` and `EventRecorderTimerGetCount()`. 
+If you are using EventRecorder in MDK, once you deploy the `perf_counter`, it will provide the timer service for EventRecorder by implementing the following functions: `EventRecorderTimerSetup()`, `EventRecorderTimerGetFreq()` and `EventRecorderTimerGetCount()`. 
 
-If you have not modify anything in `EventRecorderConf.h`, **you don't have to**, and please keep the default configuration.  If you see warnings like this:
+If you have not modified anything in `EventRecorderConf.h`, **you don't have to**, and please keep the default configuration.  If you see warnings like this:
 
 ```
 Invalid Time Stamp Source selected in EventRecorderConf.h!
@@ -329,7 +329,7 @@ Please set the macro `EVENT_TIMESTAMP_SOURCE` to `3` to suppress it.
 
 
 
-**By using perf_counter as the reference clock, EventRecorder can have the highest clock resolution on the target system without worring about the presence of DWT or any conflicting usage of SysTick.** 
+**By using perf_counter as the reference clock, EventRecorder can have the highest clock resolution on the target system without worrying about the presence of DWT or any conflicting usage of SysTick.** 
 
 
 
@@ -347,7 +347,7 @@ If you want to change the System Frequency, **after** the change, make sure:
 
 #### 1.6.2 Reconfigure the SysTick
 
-Some systems (e.g. FreeRTOS) might reconfigure the systick timer to fulfil the requirement of their feature. To support this:
+Some systems (e.g., FreeRTOS) might reconfigure the systick timer to fulfill the requirements of their feature. To support this:
 
 1. **Before the reconfiguration**, please call function `before_cycle_counter_reconfiguration()`.  
 
@@ -363,7 +363,7 @@ Some systems (e.g. FreeRTOS) might reconfigure the systick timer to fulfil the r
 
 #### 2.1.1 For Bare-metal:
 
-1. Clone the code to your local with following command lines:
+1. Clone the code to your local with the following command lines:
 
 ```shell
 git clone https://github.com/GorgonMeducer/perf_counter.git
@@ -374,14 +374,14 @@ git clone https://github.com/GorgonMeducer/perf_counter.git
 
 > **NOTE**: Please do **NOT** add any assembly source files of this `perf_counter` library to your compilation, i.e. `systick_wrapper_gcc.S`, `systick_wrapper_gnu.s` or `systick_wrapper_ual.s`.
 
-4. Include `perf_counter.h` in corresponding c source file:
+4. Include `perf_counter.h` in the corresponding c source file:
 
 ```c
 #include "perf_counter.h"
 ```
 
 
-5. Make sure your system contains the CMSIS (with a version 5.7.0 or above) as `perf_counter.h` includes `cmsis_compiler.h`. 
+5. Make sure your system contains the CMSIS (with version 5.7.0 or above) as `perf_counter.h` and includes `cmsis_compiler.h`. 
 6. Call the function `perfc_port_insert_to_system_timer_insert_ovf_handler()` in your `SysTick_Handler()`
 
 ```c
@@ -394,9 +394,9 @@ void SysTick_Handler(void)
 ```
 
 
-7. Make sure the `SystemCoreClock` is updated with the same value as CPU frequency. 
+7. Ensure the `SystemCoreClock` is updated with the same value as CPU frequency. 
 8. **IMPORTANT**: Make sure the `SysTick_CTRL_CLKSOURCE_Msk` bit ( bit 2) of `SysTick->CTRL` register is `1` that means SysTick runs with the same clock source as the target Cortex-M processor. 
-9. Initialize the perf_counter with boolean value that indicates whether the user applications and/or RTOS have already occupied the SysTick.
+9. Initialize the perf_counter with a boolean value that indicates whether the user applications and/or RTOS have already occupied the SysTick.
 
 ```c
 void main(void)
@@ -413,7 +413,7 @@ void main(void)
     SystemCoreClockUpdate();
     
     /*! \brief initialize perf_counter() and pass true if SysTick is 
-     *!        occupied by user applications or RTOS, otherwise pass
+     *!        occupied by user applications or RTOS; otherwise, pass
      *!        false. 
      */
     init_cycle_counter(true);
@@ -425,16 +425,16 @@ void main(void)
 }
 ```
 
-10. **IMPORTANT**: Please enable GNU extension in your compiler. For **GCC** and **CLANG**, it is `--std=gnu99` or `--std=gnu11`, and for other compilers, please check the user manual first. Failed to do so, you will not only trigger the warning in `perf_counter.h`, but also lose the function correctness of `__cycleof__()` and `__super_loop_monitor__()`, because `__PLOOC_VA_NUM_ARGS()` isn't report `0` when passed with no argument. 
+10. **IMPORTANT**: Please enable the GNU extension in your compiler. For **GCC** and **CLANG**, it is `--std=gnu99` or `--std=gnu11`, and for other compilers, please check the user manual first. Fail to do so, you will not only trigger the warning in `perf_counter.h`, but also lose the function correctness of `__cycleof__()` and `__super_loop_monitor__()`, because `__PLOOC_VA_NUM_ARGS()` doesn't report `0` when passed with no argument. 
 
 ```c
 #if __PLOOC_VA_NUM_ARGS() != 0
-#warning Please enable GNC extensions, it is required by __cycleof__() and \
+#warning Please enable GNC extensions that is required by __cycleof__() and \
 __super_loop_monitor__()
 #endif
 ```
 
-11. It is nice to add macro definition `__PERF_COUNTER__` to your project GLOBALLY. It helps other module to detect the existence of perf_counter. For Example, LVGL [`lv_conf_cmsis.h`](https://github.com/lvgl/lvgl/blob/d367bb7cf17dc34863f4439bba9b66a820088951/env_support/cmsis-pack/lv_conf_cmsis.h#L81-L99) use this macro to detect perf_counter and uses `get_system_ms()` to implement `lv_tick_get()`.
+11. It is nice to add macro definition `__PERF_COUNTER__` to your project GLOBALLY. It helps other modules to detect the existence of perf_counter. For Example, LVGL [`lv_conf_cmsis.h`](https://github.com/lvgl/lvgl/blob/d367bb7cf17dc34863f4439bba9b66a820088951/env_support/cmsis-pack/lv_conf_cmsis.h#L81-L99) use this macro to detect perf_counter and uses `get_system_ms()` to implement `lv_tick_get()`.
 
 
 
@@ -446,7 +446,7 @@ __super_loop_monitor__()
 
 1. Download the cmsis-pack from the`cmsis-pack` folder. It is a file with name `GorgonMeducer.perf_counter.<version>.pack`, for example `GorgonMeducer.perf_counter.2.2.0.pack`
 
-2. Double click it to install this cmsis-pack. Once finished, you can find it in your Pack-Installer:
+2. Double-click it to install this cmsis-pack. Once finished, you can find it in your Pack-Installer:
 
    ![](./documents/pictures/pack_installer)
    In the future, you can pull the latest version of perf_counter from the menu `Packs->Check For Updates` as shown below:
@@ -459,25 +459,25 @@ __super_loop_monitor__()
 
 ![](./documents/pictures\RTE) 
 
-4. Include `perf_counter.h` in corresponding c source file:
+4. Include `perf_counter.h` in the corresponding c source file:
 
 ```c
 #include "perf_counter.h"
 ```
 
 
-5. Make sure your system contains the CMSIS (with a version 5.7.0 or above) as `perf_counter.h` includes `cmsis_compiler.h`.  Usually, you should do this with RTE as shown below:
+5. Make sure your system contains the CMSIS (version 5.7.0 or above) as `perf_counter.h` and includes `cmsis_compiler.h`.  Usually, you should do this with RTE, as shown below:
 
 ![image-20220509012432408](./documents/pictures/RTE_cmsis_core) 
 
-6. Make sure the `SystemCoreClock` is updated with the same value as CPU frequency. 
+6. Ensure the `SystemCoreClock` is updated with the same value as CPU frequency. 
 7. **IMPORTANT**: Make sure the `SysTick_CTRL_CLKSOURCE_Msk` bit ( bit 2) of `SysTick->CTRL` register is `1` that means SysTick runs with the same clock source as the target Cortex-M processor. 
-8. Initialize the perf_counter with boolean value that indicates whether the user applications and/or RTOS have already occupied the SysTick.
+8. Initialize the perf_counter with a boolean value that indicates whether the user applications and/or RTOS have already occupied the SysTick.
 
 ```c
 void main(void)
 {
-    //! setup system clock 
+    //! Setup system clock 
 
     /*! \brief Update SystemCoreClock with the latest CPU frequency
      *!        If the function doesn't exist or doesn't work correctly,
@@ -489,7 +489,7 @@ void main(void)
     SystemCoreClockUpdate();
 
     /*! \brief initialize perf_counter() and pass true if SysTick is 
-     *!        occupied by user applications or RTOS, otherwise pass
+     *!        occupied by user applications or RTOS; otherwise, pass
      *!        false. 
      */
     init_cycle_counter(true);
@@ -501,28 +501,28 @@ void main(void)
 }
 ```
 
-9. **IMPORTANT**: Please enable GNU extension in your compiler. 
+9. **IMPORTANT**: Please enable the GNU extension in your compiler. 
 
-   For Arm Compiler 5, please select both **C99 mode** and GNU extensions in the **Option for target dialog** as shown below:
+   For Arm Compiler 5, please select both **C99 mode** and GNU extensions in the **Option for target dialogue** as shown below:
 
 ![image-20220509012752097](./documents/pictures/GNU_in_AC5) 
 
 For Arm Compiler 6, please select **gnu99** or **gnu11** in Language C drop-list as shown below:
 
 ![image-20220509012944724](./documents/pictures/gnu_in_ac6) 
 
-Failed to do so, you will not only trigger the warning in `perf_counter.h`, but also lose the function correctness of `__cycleof__()` and `__super_loop_monitor__()`, because `__PLOOC_VA_NUM_ARGS()` isn't report `0` when passed with no argument. 
+Failed to do so, you will not only trigger the warning in `perf_counter.h`, but also lose the function correctness of `__cycleof__()` and `__super_loop_monitor__()`, because `__PLOOC_VA_NUM_ARGS()` doesn't report `0` when passed with no argument. 
 
 ```c
 #if __PLOOC_VA_NUM_ARGS() != 0
-#warning Please enable GNC extensions, it is required by __cycleof__() and \
+#warning Please enable GNC extensions, that is required by __cycleof__() and \
 __super_loop_monitor__()
 #endif
 ```
 
 ### 2.3 Use perf_counter in RT-Thread RTOS
 
-perf_counter has registered as one of the [RT-Thread software packages](https://packages.rt-thread.org/en/detail.html?package=perf_counter), which locats in `system` category. In [ENV](https://www.rt-thread.io/download.html?download=Env) or [RT-Thread Studio](https://www.rt-thread.io/download.html?download=Studio), you just need to simply enable cputime framework. RT-Thread will automatically enable perf_counter if you are using Cortex-M architecture.
+perf_counter has registered as one of the [RT-Thread software packages](https://packages.rt-thread.org/en/detail.html?package=perf_counter), which locats in `system` category. In [ENV](https://www.rt-thread.io/download.html?download=Env) or [RT-Thread Studio](https://www.rt-thread.io/download.html?download=Studio), you just need to enable `cputime` framework. RT-Thread will automatically enable perf_counter if you are using Cortex-M architecture.
 
 ![rt-thread-settings](./documents/pictures/rt-thread-settings.png) 
 
@@ -534,7 +534,7 @@ perf_counter has registered as one of the [RT-Thread software packages](https://
 
 ### 3.1 Why I see `Undefined symbol $Super$$SysTick_Handler` 
 
-This error usually pops up in **Arm Compiler 5** and **Arm Compiler 6**. It is because you haven't implemented any non-weak `SysTick_Handler()`.  Please provide an EMPTY one in any c source file to solve this problem:
+This error usually appears in **Arm Compiler 5** and **Arm Compiler 6**. It is because you haven't implemented any non-weak `SysTick_Handler()`.  Please provide an EMPTY one in any c source file to solve this problem:
 
 ```c
 void SysTick_Handler(void)
@@ -546,7 +546,7 @@ void SysTick_Handler(void)
 
 ### 3.2 Why do I see perf_counter in red in the MDK project manager?
 
-Since version v2.1.0 I removed the unnecessary bundle feature from the cmsis-pack. If you have used the older version, you will encounter this issue. To solve this problem: 
+Since version v2.1.0, I removed the unnecessary bundle feature from the cmsis-pack. If you have used the older version, you will encounter this issue. To solve this problem: 
 
 1. please unselect ALL the performance components in RTE, press OK and close the uVision. 
 2. reopen the mdk project and select the perf_counter components in RTE