Philips Semiconductors
Product specification
PTN3501
Maintenance and control device
2001 Jan 17
5
Addressing
For addressing, see Figure 8.
S
0
A5
A4
A3
A2
A1
A0
0
A
A5
0
A
S
1
A4
A3
A2
A1
A0
a.
b.
(a) I/O EXPANDER
(b) MEMORY
SW00648
SLAVE ADDRESS
SLAVE ADDRESS
Figure 8. PTN3501 slave addresses
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).
S
0
A5
A4
A3
A2
A1
A0
0
A
DATA 1
A
DATA 2
A
SDA
SCL
t pv
1
2
3
4
5
6
7
8
t pv
DATA 2 VALID
DATA 1 VALID
SW00649
ACKNOWLEDGE
FROM SLAVE
R/W
START CONDITION
ACKNOWLEDGE
FROM SLAVE
ACKNOWLEDGE
FROM SLAVE
SLAVE ADDRESS (I/O EXPANDER)
DATA TO PORT
DATA TO PORT
WRITE TO
PORT
DATA OUT
FROM PORT
Figure 9. I/O WRITE mode (output)
S
0
A5
A4
A3
A2
A1
A0
1
A
DATA 1
A
DATA 4
1
SDA
t ph
t ps
DATA 4
P
DATA 2
DATA 3
SW00650
SLAVE ADDRESS (I/O EXPANDER)
DATA FROM PORT
DATA FROM PORT
READ FROM
PORT
DATA INTO
PORT
START CONDITION
ACKNOWLEDGE
FROM SLAVE
R/W
ACKNOWLEDGE
FROM MASTER
STOP
CONDITION
DATA 1
INT
t iv
t ir
Figure 10. I/O READ mode (input)
