GD32A50x User Manual
497
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
BRR [15:4]
BRR[3:0]
rw
rw
Bits
Fields
Descriptions
31:16
Reserved
Must be kept at reset value.
15:4
BRR[15:4]
Integer of baud-rate divider.
INTDIV = BRR[15:4].
3:0
BRR [3:0]
Fraction of baud-rate divider.
If OVSMOD = 0, FRADIV = BRR[3:0].
If OVSMOD = 1, FRADIV = BRR[2:0], BRR[3] must be reset.
19.4.5.
Prescaler and guard time configuration register (USART_GP)
Address offset: 0x10
Reset value: 0x0000 0000
This register has to be accessed by word (32-bit).
This register cannot be written when the USART is enabled (UEN=1).
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Reserved
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
GUAT[7:0]
PSC[7:0]
rw
rw
Bits
Fields
Descriptions
31:16
Reserved
Must be kept at reset value.
15:8
GUAT[7:0]
Guard time value in smartcard mode.
This bit field cannot be written when the USART is enabled (UEN=1).
7:0
PSC[7:0]
Prescaler value for dividing the system clock.
In IrDA Low-power mode, the division factor is the prescaler value.
00000000: Reserved - do not program this value.
00000001: divides the source clock by 1.
00000010: divides the source clock by 2.
...
In IrDA normal mode.
00000001: can be set this value only
In smartcard mode, the prescaler value for dividing the system clock is stored in
PSC[4:0] bits. And the bits of PSC[7:5] must be kept at reset value. The division