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Setup
5.4
Default Register Settings in the TCA8418E when Using the LaunchPad
Upon startup, the MSP430 LaunchPad configures the TCA8418E to work as a keypad scanner with the
following values:
Table 2. Default TCA8418E Register Values When Using the LaunchPad
Register
Register Name
Default Value for EVM
Comment
0x00
Reserved
0x97
Interrupts enabled (except Overflow)
0x01
CFG
0x00
0x02
INT_STAT
0x00
0x03
KEY_LCK_EC
0x00
0x04
KEY_EVENT_A
0x00
0x05
KEY_EVENT_B
0x00
0x06
KEY_EVENT_C
0x00
0x07
KEY_EVENT_D
0x00
0x08
KEY_EVENT_E
0x00
0x09
KEY_EVENT_F
0x00
0x0A
KEY_EVENT_G
0x00
0x0B
KEY_EVENT_H
0x00
0x0C
KEY_EVENT_I
0x00
0x0D
KEY_EVENT_J
0x00
0x0E
KP_LCK_TIMER
0xA7
0x0F
Unlock1
0x0C
Key #12
0x10
Unlock2
0x0C
Key #12 – Press twice to unlock
0x11
GPIO_INT_STAT1
0x00
0x12
GPIO_INT_STAT2
0x00
0x13
GPIO_INT_STAT3
0x00
0x14
GPIO_DAT_STAT1
0xFF
0x15
GPIO_DAT_STAT2
0xFF
0x16
GPIO_DAT_STAT3
0x03
0x17
GPIO_DAT_OUT1
0x00
0x18
GPIO_DAT_OUT2
0x00
0x19
GPIO_DAT_OUT3
0x00
0x1A
GPIO_INT_EN1
0x00
0x1B
GPIO_INT_EN2
0x00
0x1C
GPIO_INT_EN3
0x00
0x1D
KP_GPIO1
0xFF
ROW0 through ROW7: keypad scan
0x1E
KP_GPIO2
0xFF
COL0 through COL7: keypad scan
0x1F
KP_GPIO3
0x00
0x20
GPI_EM1
0x00
0x21
GPI_EM2
0x00
0x22
GPI_EM3
0x00
0x23
GPIO_DIR1
0x00
0x24
GPIO_DIR2
0x00
0x25
GPIO_DIR3
0x00
0x26
GPIO_INT_LVL_1
0x00
0x27
GPIO_INT_LVL_2
0x00
0x28
GPIO_INT_LVL_3
0x00
0x29
DEBOUNCE_DIS_1
0x00
0x2A
DEBOUNCE_DIS_2
0x00
0x2B
DEBOUNCE_DIS_3
0x00
10
TCA8418E Keypad Scan EVM
SLVUAA2 – August 2014
Copyright © 2014, Texas Instruments Incorporated