ST7571 datasheet(20/76 Pages) SITRONIX

20 / 76 page

ST7571

Ver 1.5a

20/76

2009/7/21

The sequence is initiated with a START condition (S) from the I

2C Interface master, which is followed by the slave address.

All slaves with the corresponding address acknowledge in parallel, all the others will ignore the I

2C Interface transfer. After

acknowledgement, one or more command words are followed and define the status of the addressed slaves. A command

word consists of a control byte, which defines Co and A0, and a data byte.

The last control byte is tagged with a cleared most significant bit (i.e. the continuation bit Co). After a control byte with a

cleared Co bit, only data byte(s) will follow. The state of the A0 bit defines whether the following data bytes are interpreted

as commands or as RAM data. All addressed slaves on the bus also acknowledge the control and data bytes. After the last

control byte either a series of display data bytes or command data bytes may follow (depending on the A0 bit setting).

If the A0 bit of the last control byte is set to logic 1, these data bytes (display data bytes) will be stored in the display RAM at

the address specified by the internal data pointer. The data pointer is automatically updated and the data is directed to the

intended ST7571 device.

If the A0 bit of the last control byte is set to logic 0, these data bytes (command data byte) will be decoded and the setting of

ST7571 will be changed according to the received commands.

Only the addressed slave makes the acknowledgement after each byte. At the end of the transmission the bus master

issues a STOP condition (P). If no acknowledge is generated by the master after a byte, the driver stops transferring data to

the master.

Fig 9.

2C Interface protocol

Last control byte. Only a stream of data bytes is allowed to follow.

This stream may only be terminated by a STOP or RE-START condition.

Another control byte will follow the data byte.

ST7571 Datasheet(PDF) 20 Page - Sitronix Technology Co., Ltd.