MCP23016-I/P Microchip Technology, MCP23016-I/P Datasheet - Page 13

• Manufacturer Part Number: MCP23016-I/P
• Description: 16-Bit I2C I/O Expander
• Manufacturer: Microchip Technology

1.9.2
To write to a MCP23016 register, the Master I
needs to follow the requirements, as illustrated in
Figure 1-3. First, the device is selected by sending the
slave address and setting the R/W bit to logic ‘0’. The
command byte is sent after the address and
determines which register will be written. Table 1-3
shows the relationship of the command byte and
register.
The MCP23016 has twelve 8-bit registers. They are
configured to operate as six 16-bit register pairs,
supporting the device’s 16-bit port. These pairs are
formed based on their functions (e.g., GP0 and GP1
are grouped together). The I
register pair to provide faster access. The first data
byte following a command byte is written into the
register pointed to by the command byte, while the
second data is written into another register in the same
pair. For example, if the first byte is sent to OLAT1
(command byte 03h), the next data byte will be written
into the second register of that pair, OLAT0. If the first
byte is written to OLAT0 (command byte 02h), the
second byte will be written to OLAT1.
There is no limitation on the number of data bytes in
one write transmission. Figure 1-4 shows the case of
multiple byte writes in one write operation. In this case,
the multiple writes are made to the same data pair.
2003 Microchip Technology Inc.
Note:
WRITING THE REGISTERS
The bus must remain free until after the
ninth clock pulse for a minimum of 12 µs
(see Table 2-5 and Figure 2-4).
2
C commands apply to one
2
C device
FIGURE 1-3:
WRITE TO CONFIGURATION
REGISTERS (CASE 1)
MCP23016
DS20090B-page 13