MAX1233_05 Datasheet, PDF (25/45 Pages) Maxim Integrated Products – ±15kV ESD-Protected Touch-Screen Controllers Include DAC and Keypad Controller

±15kV ESD-Protected Touch-Screen
Controllers Include DAC and Keypad Controller
allowing certain keys to be masked from detection.
Tables 18–21 show the programmable bits of the keypad
control register. Tables 23, 24, and 25 show the program-
mable bits of the keypad mask registers. The Keypad
Controller and GPIO section provides more details.
GPIO Control Register
The GPIO control register and the GPIO pullup register
allow the keypad controller’s row and column inputs to be
configured as up to eight parallel I/O pins. Tables 26 and
27 show the GPIO control register layout and control reg-
ister descriptions. Tables 28 and 29 show the GPIO pullup
disable register and associated descriptions. For more
information, see the Applications Information section.
Table 21. Keypad Hold Time Control
HLD2
0
0
0
0
1
1
1
1
HLD1
0
0
1
1
0
0
1
1
HLD0
0
1
0
1
0
1
0
1
FUNCTION
If a button is held, wait 100µs before beginning next debounce scan
If a button is held, wait 1 debounce time before beginning the next debounce scan
If a button is held, wait 2 debounce times before beginning the next debounce scan
If a button is held, wait 3 debounce times before beginning the next debounce scan
If a button is held, wait 4 debounce times before beginning the next debounce scan
If a button is held, wait 5 debounce times before beginning the next debounce scan
If a button is held, wait 6 debounce times before beginning the next debounce scan
If a button is held, wait 7 debounce times before beginning the next debounce scan
Table 22. Keypad Key Mask Control Register
BIT15 BIT14 BIT13 BIT12 BIT11 BIT10 BIT9 BIT8 BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0
KM15 KM14 KM13 KM12 KM11 KM10 KM9 KM8 KM7 KM6 KM5 KM4 KM3 KM2 KM1 KM0
Table 23. Keypad Key Mask Control Register Descriptions—Individual Mask
BIT
NAME
DESCRIPTION
15
KM15 Mask status register data update on individual key for row 4, column 4
14
KM14 Mask status register data update on individual key for row 3, column 4
13
KM13 Mask status register data update on individual key for row 2, column 4
12
KM12 Mask status register data update on individual key for row 1, column 4
11
KM11 Mask status register data update on individual key for row 4, column 3
10
KM10 Mask status register data update on individual key for row 3, column 3
9
KM9
Mask status register data update on individual key for row 2, column 3
8
KM8
Mask status register data update on individual key for row 1, column 3
7
KM7
Mask status register data update on individual key for row 4, column 2
6
KM6
Mask status register data update on individual key for row 3, column 2
5
KM5
Mask status register data update on individual key for row 2, column 2
4
KM4
Mask status register data update on individual key for row 1, column 2
3
KM3
Mask status register data update on individual key for row 4, column 1
2
KM2
Mask status register data update on individual key for row 3, column 1
1
KM1
Mask status register data update on individual key for row 2, column 1
0
KM0
Mask status register data update on individual key for row 1, column 1
Table 24. Keypad Column Mask Control Register
BIT15 BIT14 BIT13 BIT12 BIT11 BIT10 BIT9 BIT8 BIT7 BIT6 BIT5 BIT4 BIT3 BIT2 BIT1 BIT0
CM4 CM3 CM2 CM1 0
0
0
0
0
0
0
0
0
0
0
0
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