mx8771 Clare, Inc., mx8771 Datasheet - Page 4

• Manufacturer Part Number: mx8771
• Description: 16-channel, 60v Driver Push-pull Output, I2c Interface
• Manufacturer: Clare, Inc.

MX8771
The MX8771 responds to two different slave addresses. The first address can be set from 20h to 27h by
connecting pins A2, A1, A0 according to the table below and is used to write and read from the 16-bit
data register. The second address is fixed at 28h and facilitates the simultaneous update of outputs from
multiple bytes and multiple MX8771's. The contents of the data register are transferred to the buffer
register when the i2c master issues a read command to address 28h. The data byte that is read from 28h
is a dummy byte whose value is undefined. Optionally the master can terminate the read command after
issuing the address and the read bit without actually reading a byte.
A2
0
0
0
0
1
1
1
1
RSTN OE
0
1
0
1
For the following timing examples, pin A2 = high, A1 = high, A0 = low
Write two bytes to the MX8771 data register and then update the MX8771 buffer register:
SDA
SCL
OUT
Read two bytes from the MX8771 data register:
SDA
SCL
MX8771
Drawing No. 877109
start
start
A1
0
0
1
1
0
0
1
1
0
0
1
1
address 26h, W
address 26h + R
A0
0
1
0
1
0
1
0
1
All Outputs
Hi-Z
Hi-Z
GND
i2c control
ack (slave)
i2c slave address
20 (hex)
21
22
23
24
25
26
27
7 6 5 4 3 2 1 0
ack (slave)
byte 1
7 6 5 4 3 2 1 0
byte 1
ack (slave)
7 6 5 4 3 2 1 0
ack (master)
byte 2
7 6 5 4 3 2 1 0
4
ack (slave)
byte 2
stop
start
no ack (master)
address 28h, R
stop
ack (slave)
stop here
IXYS
www.claremicronix.com
dummy read
no ack (master)
-or-
3/6/08
stop