
58
AT89C51ID2
4289C–8051–11/05
Table 39. Example of Computed Value When X2=1, SMOD1=1, SPD=1
Table 40. Example of Computed Value When X2=0, SMOD1=0, SPD=0
The baud rate generator can be used for mode 1 or 3 (refer to
Figure 23.), but also for
mode 0 for UART, thanks to the bit SRC located in BDRCON register
(Table 47.)UART Registers
Table 41. SADEN Register
SADEN - Slave Address Mask Register for UART (B9h)
Reset Value = 0000 0000b
Table 42. SADDR Register
SADDR - Slave Address Register for UART (A9h)
Reset Value = 0000 0000b
Baud Rates
F
OSC = 16. 384 MHz
F
OSC = 24MHz
BRL
Error (%)
BRL
Error (%)
115200
247
1.23
243
0.16
57600
238
1.23
230
0.16
38400
229
1.23
217
0.16
28800
220
1.23
204
0.16
19200
203
0.63
178
0.16
9600
149
0.31
100
0.16
4800
43
1.23
-
Baud Rates
F
OSC = 16. 384 MHz
F
OSC = 24MHz
BRL
Error (%)
BRL
Error (%)
4800
247
1.23
243
0.16
2400
238
1.23
230
0.16
1200
220
1.23
202
3.55
600
185
0.16
152
0.16
76
543
210
76
543
210