- 8 -

7), the last transmission is lowest (LSB, bit 0). Also must be followed by an acknowledge bit after

each byte (ACK). C transmission data shown in Figure 8.

Figure 8: Data Transfer I2 C bus

◎I C-bus response

In the I C bus data transfer process, one byte per transmission, must acknowledge with a status

bit. Receiving reception data to inform the transmitter can acknowledge bit. Acknowledge bit hosts

still generated clock pulse, and acknowledge the state of the bit data follow the principle of "Who

receives who produce", that always generates acknowledge bit by the receiver, the receiver clock

pulse response during the SDA line must be low, making it a high level during this clock pulse is

stable low (see Figure 9), of course, setup and hold times must be considered (for details please refer

to table 6). When sending data from the host to the machine, generating an acknowledge bit from the

slave; master data received from the slave, the master generates an acknowledge bit.

I C bus standards: Acknowledge bit 0 indicates the receiver acknowledge (ACK), often

abbreviated as A; it is a representation of non-response (NACK), often abbreviated as NA. The

transmitter then sends LSB, should release the SDA line (pull SDA), in order to wait for the receiver

generates an acknowledge bit.

If the receiver is receiving at the time of completion of the last byte of data, or can’t receive

more data should be generated to notify the non-response signal transmitter. If you find a receiver

transmitter generates a non-responder status, you should send a termination.

Figure 9: C bus Response

◎Slave Address

I C bus does not additional address decoder and chip select signals. Multiple with I C bus

2

2

2

2

2

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