C8051F300/1/2/3/4/5
Table 14.1. Timer Settings for Standard Baud Rates Using The Internal 24.5 MHz
Oscillator
Frequency: 24.5 MHz
Target
Baud Rate
(bps)
230400
115200
SYSCLK from
Internal Osc.
57600
28800
14400
9600
2400
1200
Baud Rate
% Error
–0.32%
–0.32%
0.15%
–0.32%
0.15%
–0.32%
–0.32%
0.15%
Oscillator Timer Clock
Divide
Source
Factor
106
212
426
848
1704
2544
10176
20448
SYSCLK
SYSCLK
SYSCLK
SYSCLK / 4
SYSCLK / 12
SYSCLK / 12
SYSCLK / 48
SYSCLK / 48
SCA1–SCA0
(pre-scale
select)
1
XX
2
XX
2
XX
2
01
00
00
10
10
T1M
1
Timer 1
Reload
Value (hex)
0xCB
0x96
0x2B
0x96
0xB9
0x96
0x96
0x2B
1
1
1
0
0
0
0
0
Notes:
1.
SCA1-SCA0 and T1M bit definitions can be found in
.
2.
X = Don’t care.
Table 14.2. Timer Settings for Standard Baud Rates Using an External 25 MHz
Oscillator
Frequency: 25.0 MHz
Target
Baud Rate
(bps)
230400
115200
SYSCLK from
External Osc.
57600
28800
14400
9600
2400
1200
SYSCLK from
Internal Osc.
57600
28800
14400
9600
Baud Rate
% Error
–0.47%
0.45%
–0.01%
0.45%
–0.01%
0.15%
0.45%
–0.01%
–0.47%
–0.47%
0.45%
0.15%
Oscillator Timer Clock
Divide
Source
Factor
108
218
434
872
1736
2608
10464
20832
432
864
1744
2608
SYSCLK
SYSCLK
SYSCLK
SYSCLK / 4
SYSCLK / 4
EXTCLK / 8
SYSCLK / 48
SYSCLK / 48
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
EXTCLK / 8
SCA1–SCA0
(pre-scale
select)
1
XX
2
XX
2
XX
2
01
01
11
10
10
11
11
11
11
T1M
1
Timer 1
Reload
Value (hex)
0xCA
0x93
0x27
0x93
0x27
0x5D
0x93
0x27
0xE5
0xCA
0x93
0x5D
1
1
1
0
0
0
0
0
0
0
0
0
Notes:
1.
SCA1–SCA0 and T1M bit definitions can be found in
.
2.
X = Don’t care
134
Rev. 2.6
ETC [ ETC ]
