Philips Semiconductors

Product data

PCA9556

2002 Mar 28

6

SIMPLIFIED SCHEMATIC OF I/O1 TO I/O7

WRITE PULSE

DATA FROM

SHIFT REGISTER

I/O0 TO I/O15

WRITE

CONFIGURATION

PULSE

D

FF

Q

D

Q

FF

D

Q

FF

D

Q

FF

INPUT PORT

REGISTER

POLARITY

INVERSION

REGISTER

OUTPUT

PORT

REGISTER

DATA FROM

SHIFT REGISTER

DATA FROM

SHIFT REGISTER

WRITE POLARITY

PULSE

CONFIGURATION

REGISTER

OUTPUT PORT

REGISTER DATA

INPUT PORT

REGISTER DATA

POLARITY

REGISTER DATA

READ PULSE

ESD PROTECTION DIODE

ESD PROTECTION DIODE

SW00796

Q

Q

Q

Q

NOTE:

On power–up or reset, all registers return to default values.

Figure 5. Simplified schematic of I/O1 to I/O7