Datasheet

Table 31. Port Scanning Function Allocation
Table 30. GPIO Data Register
Table 29. Odd Individual Segment Intensity Format
KEYS
SCANNED
PORTS
AVAILABLE
P0 P1 P2 P3 P4
None 5 pins GPIO GPIO GPIO GPIO GPIO
1 to 8 3 pins Key_A GPIO GPIO GPIO IRQ
9 to 16 2 pins Key_A Key_B GPIO GPIO IRQ
17 to 24 1 pin Key_A Key_B Key_C GPIO IRQ
25 to 36 None Key_A Key_B Key_C Key_D IRQ
MODE
ADDRESS
CODE (HEX)
REGISTER DATA
D7 D6 D5 D4 D3 D2 D1 D0
Write GPIO Data 0x05 X X X P4 P3 P2 P1 P0
Read GPIO Data 0x85 0 0 0 P4 or IRQ status P3 P2 P1 P0
DUTY
CYCLE
TYPICAL
SEGMENT
CURRENT (mA)
ADDRESS
CODE
(HEX)
REGISTER DATA
HEX
CODE
D7 D6 D5 D4 D3 D2 D1 D0
1/16 (min on) 2.5 0x10 to 0x17 0 0 0 0
See Table 28.
0x0X
2/16 5 0x10 to 0x17 0 0 0 1 0x1X
3/16 7.5 0x10 to 0x17 0 0 1 0 0x2X
4/16 10 0x10 to 0x17 0 0 1 1 0x3X
5/16 12.5 0x10 to 0x17 0 1 0 0 0x4X
6/16 15 0x10 to 0x17 0 1 0 1 0x5X
7/16 17.5 0x10 to 0x17 0 1 1 0 0x6X
8/16 20 0x10 to 0x17 0 1 1 1 0x7X
9/16 22.5 0x10 to 0x17 1 0 0 0 0x8X
10/16 25 0x10 to 0x17 1 0 0 1 0x9X
11/16 27.5 0x10 to 0x17 1 0 1 0 0xAX
12/16 30 0x10 to 0x17 1 0 1 1 0xBX
13/16 32.5 0x10 to 0x17 1 1 0 0 0xCX
14/16 35 0x10 to 0x17 1 1 0 1 0xDX
15/16 37.5 0x10 to 0x17 1 1 1 0 0xEX
15/16 (max on) 37.5 0x10 to 0x17 1 1 1 1 0xFX
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Maxim Integrated │ 28
MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display
Driver with I/O Expander and Key Scan