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Serial Interface I2C

Serial Interface I2C

Through the interface I2C data is transferred in synchronous mode. Information SDA line is bi-directional. Synchronize signals SCL produces a device (master). The speed of data transfer is 400 Kbit/sek. 1 bit/sek = 1 Bd. Fig.1 - Temporary figure protocol exchange.

Fig. 1. Temporary Figure Protocol Exchange.

Start carried out at a negative SDA front at the time when SCL is positive. The data bits strobe by the positive Front SCL. After the zero-bit data a receiver shapes low-level signals on the line SDA, responding by Ask signal. Stop signal carried out at a positive SDA front at the time when SCL is positive.



Each device has its own address, and determined the first byte. 7b, 6b, 5b, 4b – the type of device. 3b, 2b, 1b – devices number of this type. 0b = 0-Record; 0b = 1-reading.

Fig. 2. Data Recording Interface.

Fig. 3. Reading Data from the Current Address.

Fig. 4. Reading Data from Random Addresses.
(Click to enlarge)

In Fig. 2 shows the data recording mode interface, in fig.3 -reading data from the current address. Fig.4 - reading data from random addresses. If an address is more than 256 bytes, a high byte is sent at first, and after him - junior.Если адрес имеет более чем 256 байт, то сначала посылается старший байт, а за ним - младший.

SDA and SCL lines are with opened open-collector.

added 23.07.07 19:08:43 | looked over 1848 times