# (E1, E21)Is level of difference between actual and nominal baud rates a problem?

Latest Updated:12/01/2011

## Question:

Since the baud rate is determined by division of the internal clock, the actual baud rate varies slightly from the nominal value of the baud rate.

For example, when inputting a 16MHz or 32MHz clock, there is a difference of 0.16%. (Nominal value: 9600bps; Actual value: 9615bps)

Is this level of difference between the actual and nominal baud rates a problem?

For example, when inputting a 16MHz or 32MHz clock, there is a difference of 0.16%. (Nominal value: 9600bps; Actual value: 9615bps)

Is this level of difference between the actual and nominal baud rates a problem?

## Answer:

In normal cases, this variation should not be a problem.

For normal UART, the margin is approximately 45% of the bit length.

When this is divided by the total bit length, the figure is a little under 4%, and even if the transmitting side and the receiving side consume half of this figure,

it is a little under 2%. Thus 0.16% is not at all a problem.

For normal UART, the margin is approximately 45% of the bit length.

When this is divided by the total bit length, the figure is a little under 4%, and even if the transmitting side and the receiving side consume half of this figure,

it is a little under 2%. Thus 0.16% is not at all a problem.

**Suitable Products**

RL78 Family |

78K Family |