Datasheet

Table 3. Register Address Map
REGISTER
COMMAND ADDRESS
HEX
CODE
D15 D14 D13 D12 D11 D10 D9 D8
No-Op R/W 0 0 0 0 0 0 0 0x00
Configuration R/W 0 0 0 0 1 0 0 0x04
Transition Detect Mask R/W 0 0 0 0 1 1 0 0x06
Factory Reserved. Do not write to this. R/W 0 0 0 0 1 1 1 0x07
Port Configuration P7, P6, P5, P4 R/W 0 0 0 1 0 0 1 0x09
Port Configuration P11, P10, P9, P8 R/W 0 0 0 1 0 1 0 0x0A
Port Configuration P15, P14, P13, P12 R/W 0 0 0 1 0 1 1 0x0B
Port Configuration P19, P18, P17, P16 R/W 0 0 0 1 1 0 0 0x0C
Port Configuration P23, P22, P21, P20 R/W 0 0 0 1 1 0 1 0x0D
Port Configuration P27, P26, P25, P24 R/W 0 0 0 1 1 1 0 0x0E
Port Configuration P31, P30, P29, P28 R/W 0 0 0 1 1 1 1 0x0F
Port 0 only (virtual port, no action) R/W 0 1 0 0 0 0 0 0x20
Port 1 only (virtual port, no action) R/W 0 1 0 0 0 0 1 0x21
Port 2 only (virtual port, no action) R/W 0 1 0 0 0 1 0 0x22
Port 3 only (virtual port, no action) R/W 0 1 0 0 0 1 1 0x23
Port 4 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 0 1 0 0 0x24
Port 5 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 0 1 0 1 0x25
Port 6 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 0 1 1 0 0x26
Port 7 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 0 1 1 1 0x27
Port 8 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 0 0 0 0x28
Port 9 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 0 0 1 0x29
Port 10 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 0 1 0 0x2A
Port 11 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 0 1 1 0x2B
Port 12 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 1 0 0 0x2C
Port 13 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 1 0 1 0x2D
Port 14 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 1 1 0 0x2E
Port 15 only (data bit D0. D7–D1 read as 0) R/W 0 1 0 1 1 1 1 0x2F
Port 16 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 0 0 0 0x30
Port 17 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 0 0 1 0x31
Port 18 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 0 1 0 0x32
Port 19 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 0 1 1 0x33
Port 20 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 1 0 0 0x34
Port 21 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 1 0 1 0x35
Port 22 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 1 1 0 0x36
Port 23 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 0 1 1 1 0x37
Port 24 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 1 0 0 0 0x38
Port 25 only (data bit D0. D7–D1 read as 0) R/W 0 1 1 1 0 0 1 0x39
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MAX7301 4-Wire-Interfaced, 2.5V to 5.5V,
20-Port and 28-Port I/O Expander