Arbitrary BAUD Rate of UART in PSoC 3/5

Question: The UART datasheet of PSoC 3/5 specifies BAUD rates from 110 – 921600bps or arbitrary up to 4Mbps. What is meant by the arbitrary rate?



There are two possible ways to select the baud rate for the UART.  The first is by selecting the baud rate from the drop down list for the "Bits per second" parameter.  This list has standard baud rates from 110bps to 921.600kbps.  When the baud rate is selected from this list, the PSoC Creator automatically configures the internal clock.  

On the other hand, when the "External Clock" option is selected from the Advanced tab, the baud rate of the UART will be 1/8th of the Clock input.  When this option is selected, the UART component has a Clock input pin to which an external clock can be connected.  This will be the arbitrary baud rate and can be upto 4Mbps, ie, the clock input to the UART component can be upto 32MHz.