MCP23009 Microchip Technology Inc., MCP23009 Datasheet - Page 12

• Manufacturer Part Number: MCP23009
• Description: 8-bit I/o Expander With Open-drain Outputs
• Manufacturer: Microchip Technology Inc.

MCP23009/MCP23S09
FIGURE 1-5:
1.4.2
The MCP23009 is a slave I
bit slave addressing, with the read/write bit filling out
the control byte. The slave address contains four fixed
bits and three user-defined hardware address bits
(configured via ADDR pin).
control byte format.
1.4.3
The MCP23S09 is a slave SPI device. The slave
address contains seven fixed bits(no address bits) with
the read/write bit filling out the control byte.
shows the control byte format.
DS22121A-page 12
i2c_clk
i2c_addr[2:0]
V
adc_en
DD
ADDRESSING I
(MCP23009)
ADDRESSING SPI DEVICES
(MCP23S09)
t
ADEN
HARDWARE ADDRESS DECODE TIMING
2
C device that supports 7-
t
2
ADDRLAT
C DEVICES
Figure 1-6
shows the
Figure 1-7
FIGURE 1-6:
FIGURE 1-7:
Start
bit
CS
S
t
ADDIS
0
0
R/W = 0 = write
R/W = 1 = read
R/W = 0 = write
R/W = 1 = read
1
1
Slave Address
Slave Address
0
0
Control Byte
Control Byte
I
FORMAT
SPI CONTROL BYTE
FORMAT
0
2
0
© 2008 Microchip Technology Inc.
C™ CONTROL BYTE
A2 A1 A0 R/W ACK
0
R/W bit
ACK bit
R/W bit
0
0
R/W