Possible baud rates for UART (RS232, RS485, RS422, virtual COM port over USB)

This site describes the difference between desired and actually achievable baud rates.
(Important only for high baud rates)

Formula

The achievable baud rates can be calculated trough this formula:

baud rate = peripheral speed / (16 * divisor value)

The divisor value is automatically calculated by the ZBrain-SDK according to the desired baud rate.(The divisor value is not user setable).
Since the divisor value is an integer value not every baud rate can be set to the exact value. The higher the baud rate, the smaller the chance to be able to set a matching baud rate at the other side of the line.

Example

The achievable baud rates can be tested with the uart test speed example.

Table

The following table is an example for the ZMC running at full speed (default). The peripheral speed in that case is 131,25MHz

standard baud rate	divisor value	achieved baud rate
300	27344	300.00
600	13672	599.99
1200	6836	1199.99
1800	4557	1800.12
2400	3418	2399.98
4800	1709	4799.96
7200	1139	7202.04
9200	892	9196.33
14400	570	14391.45
19200	427	19211.07
38400	214	38332.36
57600	142	57768.49
115200	71	115536.97
230400	36	227864.58
460800	18	455729.17
	15	546875.00
	16	512695.31
	15	546875.00
	14	585937.50
	13	631009.62
	12	683593.75
	11	745738.64
vvv might not work vvv
	10	820312.50
921600	9	911458.33
	8	1025390.63
	7	1171875.00
	6	1367187.50
	5	1640625.00
	4	2050781.25
	3	2734375.00
	2	4101562.50
	1	8203125.00