ICM-20602
DATA OUTPUT BY
TRANSMITTER (SDA)
not acknowledge
DATA OUTPUT BY
RECEIVER (SDA)
acknowledge
8
SCL FROM
MASTER
1
2
9
clock pulse for
acknowledgement
START
condition
Figure 9. Acknowledge on the I2C Bus
Communications
After beginning communications with the START condition (S), the master sends a 7-bit slave address followed by an 8th bit, the
read/write bit. The read/write bit indicates whether the master is receiving data from or is writing to the slave device. Then, the
master releases the SDA line and waits for the acknowledge signal (ACK) from the slave device. Each byte transferred must be
followed by an acknowledge bit. To acknowledge, the slave device pulls the SDA line LOW and keeps it LOW for the high period of
the SCL line. Data transmission is always terminated by the master with a STOP condition (P), thus freeing the communications line.
However, the master can generate a repeated START condition (Sr), and address another slave without first generating a STOP
condition (P). A LOW to HIGH transition on the SDA line while SCL is HIGH defines the stop condition. All SDA changes should take
place when SCL is low, with the exception of start and stop conditions.
SDA
SCL
1 – 7
8
9
1 – 7
8
9
1 – 7
8
9
S
P
START
STOP
ADDRESS
R/W
ACK
DATA
ACK
DATA
ACK
condition
condition
Figure 10. Complete I2C Data Transfer
To write the internal ICM-20602 registers, the master transmits the start condition (S), followed by the I2C address and the write bit
(0). At the 9th clock cycle (when the clock is high), the ICM-20602 acknowledges the transfer. Then the master puts the register
address (RA) on the bus. After the ICM-20602 acknowledges the reception of the register address, the master puts the register data
onto the bus. This is followed by the ACK signal, and data transfer may be concluded by the stop condition (P). To write multiple
bytes after the last ACK signal, the master can continue outputting data rather than transmitting a stop signal. In this case, the ICM-
20602 automatically increments the register address and loads the data to the appropriate register. The following figures show
single and two-byte write sequences.
Single-Byte Write Sequence
Master
Slave
S
AD+W
RA
DATA
P
ACK
ACK
ACK
Document Number: DS-000176
Revision: 1.0
Page 25 of 57
Revision Date: 10/03/2016
TDK [ TDK ELECTRONICS ]
