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GD32F403xx User Manual
121
00: GPIO selected
01: LXTAL clock selected
10: Reserved, equals 0 selected
11: Reserved, equals 0 selected
27
Reserved
Must be kept at reset value.
26:24
REFPSC
[2:0]
Reference signal source prescaler
These bits are set and cleared by software
000: Reference signal not divided
001: Reference signal divided by 2
010: Reference signal divided by 4
011: Reference signal divided by 8
100: Reference signal divided by 16
101: Reference signal divided by 32
110: Reference signal divided by 64
111: Reference signal divided by 128
23:16
CKLIM
[7:0]
Clock trim base limit value
These bits are set and cleared by software to define the clock trim base limit
value. These bits used to frequency evaluation and automatically trim process.
Please refer to the
Frequency evaluation and automatically trim process
for
detail.
15:0
RLVALUE
[15:0]
CTC counter reload value
These bits are set and cleared by software to define the CTC counter reload
value. These bits reload to CTC trim counter when a reference sync pulse
received to start or restart the counter.
6.4.3.
Status register (CTC_STAT)
Address offset: 0x08
Reset value: 0x0000 0000
This register has to be accessed by word (32-bit).
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
REFCAP[15:0]
r
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
REFDIR
Reserved
TRIM
ERR
REF
MISS
CKERR
Reserved
EREFIF
ERRIF
CKWARN
IF
CKOK
IF
r
r
r
r
r
r
r
r
Bits
Fields
Descriptions
31:16
REFCAP
[15:0]
CTC counter capture when reference sync pulse.