
GD32L23x User Manual
402
16
Reserved
Must be kept at reset value.
15:13
ETSEL[2:0]
External trigger select
The ETSEL bits are used to select the external trigger source for LPTIMER.
000: ETI0 (GPIO)
001: ETI1 (RTC Alarm 0)
010: ETI2 (RTC Alarm 1)
011: ETI3 (RTC_TAMP0 input detection)
100: ETI4 (RTC_TAMP1 input detection)
101: ETI5 (RTC_TAMP2 input detection)
110: ETI6 (CMP0_OUT)
111: ETI7 (CMP1_OUT)
These bits can be modified only when the LPTIMER is disabled (The LPTEN bit in
LPTIMER_CTL1 register is 0).
12
Reserved
Must be kept at reset value.
11:9
PSC[2:0]
Clock prescaler selection
The PSC bits are used to configure the prescaler to divide the timer clock
(LPTIMER_CK) to a counter clock (PSC_CLK).
000: /1
001: /2
010: /4
011: / 8
100: / 16
101: / 32
110: / 64
111: / 128
These bits can be modified only when the LPTIMER is disabled (The LPTEN bit in
LPTIMER_CTL1 register is 0).
8
Reserved
Must be kept at reset value.
7:6
TFLT[1:0]
Trigger filter
The TFLT bits are used to configure the digital filter for triggers. An internal clock
source must be used in this function.
00: Filter disabled, any active level of the trigger is valid.
01: The active level change of the trigger need to be maintained at least 2 clock
periods.
10: The active level change of the trigger need to be maintained at least 4 clock
periods.
11: The active level change of the trigger need to be maintained at least 8 clock
periods.
These bits can be modified only when the LPTIMER is disabled (The LPTEN bit in
LPTIMER_CTL1 register is 0).