PCF8570 Philips Semiconductors, PCF8570 Datasheet - Page 7

• Manufacturer Part Number: PCF8570
• Description: 256 x 8-bit static low-voltage RAM with I2C-bus interface
• Manufacturer: Philips Semiconductors

Philips Semiconductors
8.5
Before any data is transmitted on the I
always carried out with the first byte transmitted after the start procedure. The I
PCF8570 WRITE and READ cycles is shown in Figs 7, 8 and 9.
1999 Jan 06
handbook, full pagewidth
handbook, full pagewidth
256
I
2
C-bus interface
I
2
S
C-bus protocol
8-bit static low-voltage RAM with
SLAVE ADDRESS
Fig.8 Master reads after setting word address (WRITE word address; READ data).
S
acknowledgement
R/W
from slave
SLAVE ADDRESS
0 A
Fig.7 Master transmits to slave receiver (WRITE) mode.
WORD ADDRESS
2
C-bus, the device which should respond is addressed first. The addressing is
acknowledgement
R/W
from slave
0 A
acknowledgement
from slave
WORD ADDRESS
at this moment master -
transmitter becomes
master - receiver and
PCF8570 slave -
receiver becomes
slave - transmitter
A
S
7
SLAVE ADDRESS
acknowledgement
from slave
A
acknowledgement
R/W
n bytes
from slave
DATA
1
MLB930
2
A
C-bus configuration for the different
memory word address
auto increment
acknowledgement
from slave
n bytes
DATA
A
MBD822
memory word address
last byte
P
acknowledgement
auto increment
DATA
from master
memory word address
Product specification
no acknowledgement
auto increment
A
PCF8570
from master
1
P