Philips Semiconductors
Product specification
128 × 8-bit EEPROM with I2C-bus interface
PCA8581; PCA8581C
To transmit eight bytes in sequential order, begin with the lowest address bits 0 0 0. The data is written after a stop is
detected. The data is only written if complete bytes have been received and acknowledged. Writing takes a time tWR
(6 to 10 ms) during which the device will not respond to its slave address. Note that to write the next row, a new write
operation is required (start, slave address, row address, data and stop).
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from master
handbook, full pagewidth
S
SLAVE ADDRESS
0
A
X
WORD ADDRESS
A
S
SLAVE ADDRESS
1
A
DATA
A
n bytes
R/W don't
care
R/W
at this moment master -
transmitter becomes
auto increment
memory word address
master - receiver and
PCA8581(C) slave - receiver
becomes slave - transmitter
no acknowledgement
from master
DATA
1
P
last byte
auto increment
memory word address
MLB891
Fig.9 Master reads after setting word address (WRITE word address; READ data).
acknowledgement
from slave
acknowledgement
from slave
acknowledgement
from slave
handbook, full pagewidth
1
A
A
DATA
1
P
S
SLAVE ADDRESS
DATA
R/W
n bytes
last bytes
auto increment
word address
auto increment
word address
MBD824
Fig.10 Master reads slave immediately after first byte (READ mode).
An unlimited number of data bytes can be read in one operation. The address is automatically incremented. If a read
without setting the word address is performed after a write operation, the address pointer may point at a byte in the row
after the previously written row. This occurs if, during writing, the three lowest address bits (column) rolled over.
1997 Apr 02
8
NXP [ NXP ]
