Tick

This sample demonstrates the tick function of RTC.

Every time the TICK timer expires, it triggers an RTC interrupt and enters the interrupt handling function, where relevant log information is printed.

Requirements

The sample supports the following development kits:

Development Kits
Hardware Platforms	Board Name
RTL87x2G HDK	RTL87x2G EVB

For more requirements, please refer to Quick Start.

Building and Downloading

This sample can be found in the SDK folder:

Keil

Project file: samples\peripheral\rtc\tick\proj\rtl87x2g\mdk

GCC

Project file: samples\peripheral\rtc\tick\proj\rtl87x2g\gcc

To build and run the sample, follow the steps listed below:

Open sample project file.
To build the target, follow the steps listed on the Generating App Image in Quick Start.
After a successful compilation, the app bin app_MP_xxx.bin will be generated in the directory mdk\bin or gcc\bin.
To download app bin into EVB board, follow the steps listed on the MP Tool Download in Quick Start.
Press reset button on EVB board and it will start running.

Experimental Verification

When the set time is up, trigger the interrupt and enter the interrupt handler function, print the interrupt message.
```
RTC_Handler: RTC_INT_TICK
```

Code Overview

This chapter will be introduced according to the following several parts:

Source Code Directory.
Peripheral initialization will be introduced in chapter Initialization .
Functional implementation after initialization will be introduced in chapter Functional Implementation .

Source Code Directory

Project Directory: sdk\samples\peripheral\rtc\tick\proj
Source Code Directory: sdk\samples\peripheral\rtc\tick\src

Source files are currently categorized into several groups as below.

└── Project: tick
    └── secure_only_app
        └── Device                   includes startup code
            ├── startup_rtl.c
            └── system_rtl.c
        ├── CMSIS                    includes CMSIS header files
        ├── CMSE Library             Non-secure callable lib
        ├── Lib                      includes all binary symbol files that user application is built on
            └── rtl87x2g_io.lib
        ├── Peripheral               includes all peripheral drivers and module code used by the application
            ├── rtl_rcc.c
            ├── rtl_pinmux.c
            ├── rtl_nvic.c
            └── rtl_rtc.c
        └── APP                      includes the ble_peripheral user application implementation
            ├── main_ns.c
            └── io_rtc.c

Initialization

The initialization process includes driver_rtc_init .

driver_rtc_init contains the initialization of RTC peripherals.

Reset RTC peripheral.
Set the RTC prescaler to (3200-1), RTC clock frequency is 10Hz (32K/3200).
Enable RTC tick interrupt RTC_INT_TICK.
Reset RTC count value.
Enable RTC peripheral.

RTC_DeInit();
RTC_SetPrescaler(RTC_PRESCALER_VALUE);
RTC_INTConfig(RTC_INT_TICK, ENABLE);
...
RTC_NvCmd(ENABLE);
RTC_ResetCounter();
RTC_Cmd(ENABLE);

Functional Implementation

When the TICK setting time is reached, it triggers an RTC interrupt and enters the interrupt handling function RTC_Handler.
1. Check if the RTC_INT_TICK status is set.
2. Print the information, clear the RTC TICK interrupt.

if (RTC_GetINTStatus(RTC_INT_TICK) == SET)
{
     /* Notes: DBG_DIRECT function is only used for debugging demonstrations, not for application projects.*/
     DBG_DIRECT("RTC_Handler: RTC_INT_TICK");
     // Add application code here
     RTC_ClearTickINT();
}