TCA8418E_15 Datasheet, PDF (35/50 Pages) Texas Instruments – I2C Controlled Keypad Scan IC With Integrated ESD Protection

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TCA8418E
SCPS222C – MAY 2010 – REVISED OCTOBER 2015
The debounce time for the keypad is for the columns only. The minimum time is 25 ms. All columns are scanned
once every 25 ms to detect any key presses. Two full scans are required to see if any keys were pressed. If the
first scan is done just after a key press, it will take 25 ms to detect the key press. If the first scan is down much
later than the key press, it will take 40 ms to detect a key press.
8.6.2.16 GPIO Pullup Disable Register, GPIO_PULL1–3 (Address 0x2C–0x2E)
This register enables or disables pullup registers from inputs.
A bit value of '0' will enable the internal pullup resistors. This is the default value.
A bit value of 1 will disable the internal pullup resistors.
ADDRESS
0x2C
0x3D
0x2E
Table 25. GPIO Pullup Disable Register Field Descriptions
REGISTER NAME
REGISTER DESCRIPTION
GPIO_PULL1
GPIO_PULL2
GPIO_PULL3
GPIO pullup Disable 1
GPIO pullup Disable 2
GPIO pullup Disable 3
BIT
7
6
5
4
3
2
1
0
R7PD
R6PD
R5P
D
R4PD
R3PD
R2P
D
R1PD
R0P
D
C7PD
C6PD
C5P
D
C4PD
C3PD
C2P
D
C1PD
C0P
D
N/A
N/A N/A N/A
N/A
N/A
C9PD
C8P
D
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