PCF8570 View Datasheet(PDF) - Philips Electronics
Part Name
Description
MFG CO.
'PCF8570' PDF : 20 Pages View PDF
Philips Semiconductors
256 × 8-bit static low-voltage RAM with
I2C-bus interface
Product specification
PCF8570
8.5 I2C-bus protocol
Before any data is transmitted on the I2C-bus, the device which should respond is addressed first. The addressing is
always carried out with the first byte transmitted after the start procedure. The I2C-bus configuration for the different
PCF8570 WRITE and READ cycles is shown in Figs 7, 8 and 9.
handbook, full pagewidth
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
S SLAVE ADDRESS 0 A WORD ADDRESS A
DATA
AP
R/W
n bytes
auto increment
memory word address
MBD822
Fig.7 Master transmits to slave receiver (WRITE) mode.
handbook, full pagewidth
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from master
S SLAVE ADDRESS 0 A WORD ADDRESS A S SLAVE ADDRESS 1 A
R/W
at this moment master -
R/W
transmitter becomes
master - receiver and
PCF8570 slave -
receiver becomes
slave - transmitter
DATA
A
n bytes
auto increment
memory word address
no acknowledgement
from master
MLB930
DATA
1P
last byte
auto increment
memory word address
Fig.8 Master reads after setting word address (WRITE word address; READ data).
1999 Jan 06
7
Share Link: 
