PCA8581 View Datasheet(PDF) - Philips Electronics
Part Name
Description
MFG CO.
'PCA8581' PDF : 20 Pages View PDF
Philips Semiconductors
128 × 8-bit EEPROM with I2C-bus interface
Product speciï¬cation
PCA8581; PCA8581C
7.5 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
PCA8581 WRITE and READ cycles is shown in Figs 7, 9 and 10.
handbook, full pagewidth
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
S SLAVE ADDRESS 0 A X WORD ADDRESS A
R/W don't
care
DATA
AP
WRITING
n bytes
auto increment
memory word address
t WR
MLB889
Fig.7 Master transmits to slave receiver (WRITE) mode.
After the word address, one-to-eight data bytes can be sent. The address is automatically incremented, but the four
highest address bits (row) are internally latched. Therefore all bytes are written in the same row.
An example of writing eight bytes with word address X 0 0 0 0 0 0 0 and six bytes with word address X 0 0 1 0 1 0 1 is
shown in Fig.8.
handbook, full pagewidth
Word Address (1) Row
X0000000
0
1
2
3
4
5
6
7
8
X0001...
1
X0010101
2
4
5
6
1
2
3
X0011...
3
(1) X = don’t care.
1997 Apr 02
column 0
1
2
3
4
5
6
7
MLB890
Fig.8 Writing eight and six bytes with different word addresses.
7
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