Posted on April 01, 2015 at 20:23The reference manual in section 21.3.3 to choose the clock for a timer says the following:
External clock mode2: external trigger input (ETR connected internally to LSE)
But the following description is not sufficient to count LSE cycles, the ETR_RMP field of the TIMx_OR register also needs to be set to 11, and this is only mentioned in the register description.
Furthermore this is not implemented properly in the HAL, stm32l0xx_hal_tim_ex.h
#define TIM22_ETR_LSE ((uint32_t)0xFFFC0000)
It needs to be
#define TIM22_ETR_LSE ((uint32_t)0xFFFC0003)
I did not check the rest of those values.
