MAX7301 Maxim, MAX7301 Datasheet - Page 13

• Manufacturer Part Number: MAX7301
• Description: The MAX7301 compact, serial-interfaced I/O expander (or general-purpose I/O (GPIO) peripheral) provides microprocessors with up to 28 ports
• Manufacturer: Maxim

Table 4. Power-Up Configuration
X = Unused bits; if read, zero results.
Table 5. Configuration Register Format
Table 6. Shutdown Control (S Data Bit D0) Format
Port Register
Bits 4 to 31
Configuration
Register
Input Mask
Register
Port
Configuration
Port
Configuration
Port
Configuration
Port
Configuration
Port
Configuration
Port
Configuration
Port
Configuration
FUNCTION
REGISTER
Configuration Register
Normal Operation
FUNCTION
FUNCTION
Shutdown
4-Wire-Interfaced, 2.5V to 5.5V, 20-Port and
P11, P10, P9, P8: GPIO Inputs Without Pullup
P7, P6, P5, P4: GPIO Inputs Without Pullup
______________________________________________________________________________________
P15, P14, P13, P12: GPIO Inputs Without
P19, P18, P17, P16: GPIO Inputs Without
P23, P22, P21, P20: GPIO Inputs Without
P27, P26, P25, P24: GPIO Inputs Without
P31, P30, P29, P28: GPIO Inputs Without
Transition Detection Disabled
POWER-UP CONDITION
All Clear (Masked Off)
ADDRESS CODE
ADDRESS CODE
Shutdown Enabled
GPIO Output Low
(HEX)
(HEX)
0x04
0x04
0x04
Pullup
Pullup
Pullup
Pullup
Pullup
D7
D7
M
M
M
D6
D6
0
CODE (HEX)
0
0
ADDRESS
0x24 to
0x09
0x0A
0x0B
0x0C
0x0D
0x3F
0x04
0x06
0x0E
0x0F
28-Port I/O Expander
D5
D5
X
X
X
D7
REGISTER DATA
X
0
X
1
1
1
1
1
1
1
REGISTER DATA
D4
D4
X
X
X
D6
X
0
0
0
0
0
0
0
0
0
D5
D3
D3
X
X
0
1
1
1
1
1
1
1
X
X
X
REGISTER DATA
D4
X
X
0
0
0
0
0
0
0
0
D2
D2
X
X
X
D3
X
X
0
1
1
1
1
1
1
1
D2
X
X
0
0
0
0
0
0
0
0
D1
D1
X
X
X
D1
X
X
0
1
1
1
1
1
1
1
D0
D0
S
0
1
D0
0
0
0
0
0
0
0
0
0
0
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