8.5.1.1.1.3 UART Baud Rate Selection

The baud rate of the communications channel to the host is selectable between 125k-250k-500k-1Mbps baud rates. The default rate after a communications reset is 250kMbps. The default rate after a Digital Reset is the rate selected by the value stored in OTP for the COMM_CTRL[BAUD] bits. When a new baud rate is selected, the new rate takes effect after the complete reception of a valid frame containing the new setting including the CRC. The next frame is sent at the new baud rate and all further frames are transmitted at the new rate. It is possible to change the baud rate at any time. After changing the baud rate, wait a minimum of 10μs before sending the first frame at the new baud rate. The value in the COMM_CTRL[BAUD] affects the baud rate used in microcontroller communications on the TX and RX pins and the response baud rate of the daisy chain. The current baud rate setting for the device is read in the COMM_STAT[BAUD_STAT] bits. This reflects the actual baud rate used whether it be set by COMM_CTRL[BAUD] or to hardware default (after communications reset).