This opcode starts data conversions. Tie the START pin low to control conversions by command. If conversions are in progress this command has no effect. The STOP opcode command is used to stop conversions. If the START command is immediately followed by a STOP command then have a gap of 4 tCLK cycles between them. When the START opcode is sent to the device, keep the START pin low until the STOP command is issued. (See the START subsection of the SPI Interface section for more details.) There are no restrictions on the SCLK rate for this command and it can be issued any time.