8051 type Microprocessor Standard Baud Rate Tables


Note: If you are using one of the Clock-Doubled 8051 derivatives such as the Philips P89C66x
you will end up running at double the baud rate shown in the table.

Not all micros can operate at all of the frequencies listed.

These tables show 8 bit auto-reload values for Timer1
set up as a baud rate generation source.

29.4912 Mhz, PCON=0

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
38,400 FEh 38,400.00 0.00%
19,200 FCh 19,200.00 0.00%
9,600 F8h 9,600.00 0.00%
4,800 F0h 4,800.00 0.00%
2,400 E0h 2,400.00 0.00%
1,200 C0h 1,200.00 0.00%
600 80h 600.00 0.00%
300 00h 300.00 0.00%




18.432 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
19,200 FBh 19,200.00 0.00%
9,600 F6h 9,600.00 0.00%
4,800 ECh 4,800.00 0.00%
2,400 D8h 2,400.00 0.00%
1,200 B0h 1,200.00 0.00%
600 60h 600.00 0.00%




16.0 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
9,600 F7h 9,259.26 -3.54%
4,800 EFh 4,901.96 2.13%
2,400 DDh 2,380.95 -0.79%
1,200 BBh 1,207.73 0.65%
600 75h 599.52 -0.07%




14.31818 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
38,400 FEh 37,286.93 -2.89%
19,200 FCh 18,643.46 -2.89%
9,600 F8h 9,321.73 -2.89%
4,800 F0h 4,660.87 -2.89%
2,400 E1h 2,405.61 0.24%
1,200 C2h 1,202.80 0.24%
600 84h 601.40 0.24%
300 07h 299.49 -0.16%




12.0 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
4,800 F3h 4,807.69 0.17%
2,400 E6h 2,403.85 0.17%
1,200 CCh 1,201.92 0.17%
600 98h 600.96 0.17%
300 30h 300.48 0.17%




11.059Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
57,600 FFh 57,598.96 0.00%
19,200 FDh 19,199.65 0.00%
9,600 FAh 9,599.83 0.00%
4,800 F4h 4,799.91 0.00%
2,400 E8h 2,399.96 0.00%
1,200 D0h 1,199.98 0.00%
600 A0h 599.99 0.00%
300 40h 299.99 0.00%




10.0 MHZ, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
4,800 F5h 4,734.85 -1.35%
2,400 EAh 2,367.42 -1.35%
1,200 D5h 1,211.24 0.94%
600 A9h 598.66 -0.22%
300 52h 299.33 -0.22%




8.00 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
4,800 F7h 4,629.63 -3.54%
2,400 EFh 2,450.98 2.13%
1,200 DDh 1,190.48 -0.79%
600 BBh 603.86 0.65%
300 75h 299.76 -0.07%




7.3728 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
38,400 FFh 38,400.00 0.00%
19,200 FEh 19,200.00 0.00%
9,600 FCh 9,600.00 0.00%
4,800 F8h 4,800.00 0.00%
2,400 F0h 2,400.00 0.00%
1,200 E0h 1,200.00 0.00%
600 C0h 600.00 0.00%
300 80h 300.00 0.00%




6.00 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
2,400 F3h 2,403.85 0.17%
1,200 E6h 1,201.92 0.17%
600 CCh 600.96 0.17%




4.00 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
2,400 F7h 2,314.81 -3.54%
1,200 EFh 1,225.49 2.13%
1,200 EEh 1,157.41 -3.54%
600 DDh 595.24 -0.79%




3.6864 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
19,200 FFh 19,200.00 0.00%
9,600 FEh 9,600.00 0.00%
4,800 FCh 4,800.00 0.00%
2,400 F8h 2,400.00 0.00%
1,200 F0h 1,200.00 0.00%
600 E0h 600.00 0.00%
300 C0h 300.00 0.00%




3.579 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
19,200 FFh 18,640.63 -2.91%
9,600 FEh 9,320.31 -2.91%
4,800 FCh 4,660.16 -2.91%
2,400 F8h 2,330.08 -2.91%
1,200 F1h 1,242.71 3.56%
1,200 F0h 1,165.04 -2.91%




1.8432 Mhz, PCON=1

Desired
Baud Rate		 TH1
Reload
Value		 Actual
Baud Rate		 Deviation
9,600 FFh 9,600.00 0.00%
4,800 FEh 4,800.00 0.00%
2,400 FCh 2,400.00 0.00%
1,200 F8h 1,200.00 0.00%
600 F0h 600.00 0.00%