Table 304. Lptim1 Input 1 Connection; Table 305. Lptim1 Input 2 Connection - ST STM32G4 Series Reference Manual

Low-power timer (LPTIM)
31.4.3 LPTIM reset and clocks
The LPTIM can be clocked using several clock sources. It can be clocked using an internal
clock signal which can be chosen among APB, LSI, LSE or HSI16 sources through the
Reset and Clock controller (RCC). Also, the LPTIM can be clocked using an external clock
signal injected on its external Input1. When clocked with an external clock source, the
LPTIM may run in one of these two possible configurations:
• The first configuration is when the LPTIM is clocked by an external signal but in the
same time an internal clock signal is provided to the LPTIM either from APB or any
other embedded oscillator including LSE, LSI and HSI16.
•
The second configuration is when the LPTIM is solely clocked by an external clock
source through its external Input1. This configuration is the one used to realize Timeout
function or Pulse counter function when all the embedded oscillators are turned off
after entering a low-power mode.
Programming the CKSEL and COUNTMODE bits allows controlling whether the LPTIM will
use an external clock source or an internal one.
When configured to use an external clock source, the CKPOL bits are used to select the
external clock signal active edge. If both edges are configured to be active ones, an internal
clock signal should also be provided (first configuration). In this case, the internal clock
signal frequency should be at least four times higher than the external clock signal
frequency.
1420/2083
Table 303. LPTIM1 external trigger connection (continued)
TRIGSEL
lptim_ext_trig11
lptim_ext_trig12

Table 304. LPTIM1 input 1 connection

lptim_in1_mux
lptim_in1_0
lptim_in1_1
lptim_in1_2
lptim_in1_3
lptim_in1_4

Table 305. LPTIM1 input 2 connection

lptim_in2_mux
lptim_in2_0
lptim_in2_1
lptim_in2_2
lptim_in2_3
lptim_in2_4
RM0440 Rev 1
External trigger
COMP6_OUT
COMP7_OUT
LPTIM1 input 1 connected to
GPIO pin as LPTIM1_IN1 alternate function
COMP1
COMP3
COMP5
COMP7
LPTIM1 input 2 connected to
GPIO pin as LPTIM1_IN2 alternate function
COMP2
COMP4
COMP6
COMP6
RM0440