3.11. Keypad Interface

Pin Signal Description type I/O
72 KP_COL[0] Keypad Column selection signals. VDDIO  
73 KP_COL[1]   VDDIO  
74 KP_COL[2]   VDDIO  
75 KP_COL[3]   VDDIO  
76 KP_COL[4]   VDDIO  
77 KP_ROW[0] Keypad Row selection signals. VDDIO  
78 KP_ROW[1]   VDDIO  
79 KP_ROW[2]   VDDIO  
80 KP_ROW[3]   VDDIO  
81 KP_ROW[4]   VDDIO  
Module Remark
TX28 A PCA9554 8-bit I2C-bus I/O port is used for KP_COL[0-3] and KP_ROW[0-3]. KP_COL[4], KP_ROW[4] is not part of the keypad interface, used for CAN instead.
TX25, TX48, TX53, TX6 KP_COL[4], KP_ROW[4] can also be used for the 1st CAN interface.

The Keypad Port (KPP) is designed to interface with the keypad matrix with 2-point contact or 3-point contact keys. The KPP is designed to simplify the software task of scanning a keypad matrix. With appropriate software support, the KPP is capable of detecting, debouncing, and decoding one or multiple keys pressed simultaneously on the keypad.

../../_images/keypad_interface.png