MAX7300 Maxim, MAX7300 Datasheet - Page 15

• Manufacturer Part Number: MAX7300
• Description: The MAX7300 compact, serial-interfaced, I/O expansion peripheral provides microprocessors with up to 28 ports
• Manufacturer: Maxim

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