The low level routines are then put together into command sequences. Finally, the command structure specific to the DS1624 is discussed. The I2C Bus - Low Level Routines. Thus, in line 2, SDA is brought high. Thus, in line 1, SCL is set to zero prior to bringing SDA high.
Data is sent by the master as bytes.
Each bit is sent by bringing SDA to the appropriate state with SCL low and then momentarily bringing SCL high, beginning with the most significant bit. After the master sends a byte, the master sends an additional clock to allow the slave to acknowledge the byte. The master brings the SCL lead high and reads the data bit and then brings the SCL lead low. This is repeated for each of the eight bits, beginning with the most significant bit. After receipt of the byte, the master is expected to acknowledge by bringing SDA low and sending a clock pulse.