C8051T630 Datasheet, PDF (155/221 Pages) Silicon Laboratories – Mixed-Signal Byte-Programmable EPROM MCU

C8051T630/1/2/3/4/5
Table 22.1. Timer Settings for Standard Baud Rates
Using The Internal 24.5 MHz Oscillator
Frequency: 24.5 MHz
Target
Baud Rate
(bps)
230400
115200
Baud Rate Oscillator Timer Clock
% Error Divide
Source
Factor
–0.32%
106
SYSCLK
–0.32%
212
SYSCLK
SCA1–SCA0
(pre-scale
select)¹
XX²
XX
57600
0.15%
426
SYSCLK
XX
28800
–0.32%
848
SYSCLK/4
01
14400
0.15%
1704 SYSCLK/12
00
9600
–0.32%
2544 SYSCLK/12
00
2400
–0.32%
10176 SYSCLK/48
10
1200
0.15%
20448 SYSCLK/48
10
Notes:
1. SCA1–SCA0 and T1M bit definitions can be found in Section 24.1.
2. X = Don’t care.
T1M^{1 Timer 1}
Reload
Value (hex)
1
0xCB
1
0x96
1
0x2B
0
0x96
0
0xB9
0
0x96
0
0x96
0
0x2B
Table 22.2. Timer Settings for Standard Baud Rates
Using an External 22.1184 MHz Oscillator
Frequency: 22.1184 MHz
Target
Baud Rate
(bps)
230400
115200
57600
28800
14400
9600
2400
1200
230400
115200
57600
28800
14400
9600
Baud Rate Oscillator Timer Clock
% Error Divide
Source
Factor
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
96
192
384
768
1536
2304
9216
18432
96
192
384
768
1536
2304
SYSCLK
SYSCLK
SYSCLK
SYSCLK / 12
SYSCLK / 12
SYSCLK / 12
SYSCLK / 48
SYSCLK / 48
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
SCA1–SCA0
(pre-scale
select)¹
XX²
XX
XX
00
00
00
10
10
11
11
11
11
11
11
Notes:
1. SCA1–SCA0 and T1M bit definitions can be found in Section 24.1.
2. X = Don’t care.
T1M^{1 Timer 1}
Reload
Value (hex)
1
0xD0
1
0xA0
1
0x40
0
0xE0
0
0xC0
0
0xA0
0
0xA0
0
0x40
0
0xFA
0
0xF4
0
0xE8
0
0xD0
0
0xA0
0
0x70
Rev. 1.0
155