Philips PTN3501 Datasheet page 5

Philips Semiconductors
Maintenance and control device
Addressing
For addressing, see Figure 8.
S 0 A5
(a) I/O EXPANDER
(b) MEMORY
Asynchronous Start
Following any Start condition on the bus, a minimum of 9 SCL clock cycles must be completed before a Stop condition can be issued. The
device does not support a Stop or a repeated Start condition during this time period.
I/O OPERATIONS (see also Figure 7)
Each of the PTN3501's eight I/Os can be independently used as an input or output. Input I/O data is transferred from the port to the
microcontroller by the READ mode (See Figure 10). Output data is transmitted to the port by the I/O WRITE mode (see Figure 9).
SCL
1 2 3
SLAVE ADDRESS (I/O EXPANDER)
SDA S 0 A5 A4 A3 A2 A1
START CONDITION
WRITE TO
PORT
DATA OUT
FROM PORT
SLAVE ADDRESS (I/O EXPANDER)
SDA S 0 A5 A4 A3 A2 A1
START CONDITION
READ FROM
PORT
DATA INTO
PORT
INT
t iv
2001 Jan 17
SLAVE ADDRESS
A4 A3 A2 A1 A0 0 A
a.
Figure 8. PTN3501 slave addresses
4 5 6 7 8
DATA TO PORT
A0 0 A
R/W ACKNOWLEDGE
FROM SLAVE
Figure 9. I/O WRITE mode (output)
A0 1 A
R/W ACKNOWLEDGE
FROM SLAVE
DATA 1 DATA 2
t ph
Figure 10. I/O READ mode (input)
SLAVE ADDRESS
S 1 A5 A4 A3 A2
b.
DATA TO PORT
DATA 1 A
ACKNOWLEDGE
FROM SLAVE
DATA 1 VALID
t pv
DATA FROM PORT
DATA 1 A
ACKNOWLEDGE
FROM MASTER
DATA 3
t ps
t ir
5
Product specification
PTN3501
A1 A0 0 A
SW00648
DATA 2 A
ACKNOWLEDGE
FROM SLAVE
DATA 2 VALID
t pv
SW00649
DATA FROM PORT
1 P
DATA 4
STOP
CONDITION
DATA 4
SW00650