TIM: Two timers timeout

One timer ISR overflow will use to trigger another timer count with its own ISR active on overflow

#include "bsp.h"

int main( void )
{
    TIM_HandleTypeDef TIM6_Handler = {0};    /*TIM 6 initial structure*/
    TIM_HandleTypeDef TIM7_Handler = {0};    /*TIM 7 initial structure*/

    HAL_Init();                                    /*Init HAL library*/

    /*configure timer 6 with a preescaler of 1000 and to count up to 20000
    by default the timer get a Tfrec of 16MHz from the APB bus*/
    TIM6_Handler.Instance = TIM6;                          /*Timer TIM to configure*/
    TIM6_Handler.Init.Prescaler = 1000;                    /*preescaler Tfrec / Prescaler*/
    TIM6_Handler.Init.CounterMode = TIM_COUNTERMODE_UP;    /*count from Period value to zero*/
    TIM6_Handler.Init.Period = 20000;                      /*down count from 20000*/
    /*use the previous parameters to set configuration on TIM6*/
    HAL_TIM_Base_Init( &TIM6_Handler );
    

    /*configure timer 7 with a preescaler of 1000 and to count up to 4000
    by default the timer get a Tfrec of 16MHz from the APB bus*/
    TIM6_Handler.Instance = TIM7;                          /*Timer TIM to configure*/
    TIM6_Handler.Init.Prescaler = 1000;                    /*preescaler Tfrec / Prescaler*/
    TIM6_Handler.Init.CounterMode = TIM_COUNTERMODE_UP;    /*count from Period value to zero*/
    TIM6_Handler.Init.Period = 4000;                      /*down count from 4000*/
    /*use the previous parameters to set configuration on TIM7*/
    HAL_TIM_Base_Init( &TIM7_Handler );

    /*init the timer 6 count from zero to overflow value (20000  in this case) and trigger an interrupts*/
    HAL_TIM_Base_Start_IT( &TIM6_Handler );

    while (1)
    {

    }
}

/* when the timer TIM6 ot 7 reaches its count overflow value this function will be called by 
HAL_TIM_IRQHandler which is in turn called from the TIM6_DAC_LPTIM1_IRQHandler or 
TIM7_LPTIM2_IRQHandler interrupt vectors*/
void HAL_TIM_PeriodElapsedCallback( TIM_HandleTypeDef *htim )
{
    /*since we are using the same callback for both vector interrupts we need to inquire 
    which timer triggered the interrupt*/
    if( htim->Instance == TIM6 )
    {
        /*if TIM6, start timer 7*/
        HAL_TIM_Base_Start_IT( htim );
    }
    
    if( htim->Instance == TIM7 )
    {
        /*if TIM7, stop timer 7*/
        HAL_TIM_Base_Stop_IT( htim );
    }
}

msps.c

#include "bsp.h"

/*This fucntion is called from HAL_TIM_Init at the very begining and it is use in our case
to enable both TIM clocks and its corresponding ISR vectors*/
void HAL_TIM_Base_MspInit( TIM_HandleTypeDef *htim )
{
    /*we need to figure it out wich call to HAL_TIM_Init function was*/
    if( htim->Instance == TIM6 )
    {
        __TIM6_CLK_ENABLE();    /*enable timer 6 clock*/
        
        /*Enable interrupt vector TIM6_DAC_LPTIM1_IRQ where the CPU will jump in any of 
        the following events: TIM6, DAC and LPTIM1 */
        HAL_NVIC_SetPriority( TIM6_DAC_LPTIM1_IRQn, 2, 0 );/*se fija la prioridad a nivel 2*/
        HAL_NVIC_EnableIRQ( TIM6_DAC_LPTIM1_IRQn );
    }
    
    if( htim->Instance == TIM7 )
    {
        __TIM7_CLK_ENABLE();    /*enable timer 7 clock*/
        
        /*Enable interrupt vector TIM7_LPTIM2_IRQ where the CPU will jump in any of 
        the following events: TIM7 and LPTIM2 */
        HAL_NVIC_SetPriority( TIM7_LPTIM2_IRQn, 2, 0 );/*se fija la prioridad a nivel 2*/
        HAL_NVIC_EnableIRQ( TIM7_LPTIM2_IRQn );
    }
}

ints.c

/*it is necesary to make a reference to TIMs control structures*/
extern TIM_HandleTypeDef TIM6_Handler;
extern TIM_HandleTypeDef TIM7_Handler;

/*Declare interrupt service rutine as it is declare in startup_stm32g0b1xx.s file*/
void TIM6_DAC_LPTIM1_IRQHandler( void )
{
    /*HAL library function that attend interrupt on TIM timers, 
    in this particular case we want the Timer6 and  we pass the control structure
    for timer 6*/
    HAL_TIM_IRQHandler( &TIM6_Handler );
}

/*Declare interrupt service rutine as it is declare in startup_stm32g0b1xx.s file*/
void TIM7_LPTIM2_IRQHandler( void )
{
    /*HAL library function that attend interrupt on TIM timers,
    in this particular case we want the Timer6 and  we pass the control structure
    for timer 7*/
    HAL_TIM_IRQHandler( &TIM7_Handler );
}