SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The keyboard controller external interface pins map on the device pads when the device IO cells are configured and multiplexed for the keypad function by the control module. For more information, see Pad Configuration Registers, and Section 29.2.1, General-Purpose Interface as a Keyboard interface.
The external keypad typically connects directly to the keyboard controller of the device (see Figure 30-2).
Figure 30-2 Typical Keyboard EnvironmentTo acheive the configuration shown in Figure 30-2 software needs to reconfigure the internal pulls on the kbd_* pads appropriately. The settings of those pads default to pull down resistors selected, software must reconfigure to pull ups on rows and to disable the pulls on columns.