PXA3xx Design Guide - Marvell

15.5.2 Keypad Matrix and Direct Keys with One Rotary EncoderThis example shows one of many possible configurations when interfacing to the PXA3xx processorfamily keypad controller. This specific configuration in Figure 55 shows the keypad controllerinterfaced to a 3 x 4 matrix keypad of 12 keys, 4 direct keys, and 1 rotary encoder. The voltagereference must be at the same level as the internal voltage domain of the keypad signals. Refer tothe Marvell ® PXA30x, PXA31x, and PXA32x Processor Electrical, Mechanical, and ThermalSpecification.Figure 55: Keypad Matrix and Direct Keys Block Diagram (with One Rotary Encoder)PWRInterruptGeneratorDirectInterfaceKP_DKINKP_DKINKP_DKINKP_DKINAComBKP_DKINKP_DKINMatrixScanKP_MKOUTKP_MKOUTKP_MKOUTKP_MKINKeypadInterfaceRegistersKP_MKINKP_MKINKP_MKINMatrixSenseMatrix Keypad (3x4)KP_MKINKP_MKINMatrix InterfaceKeypad Interface ControllerKEYPAD_003_P2Copyright © 2009 MarvellDoc. No. MV-S301368-00 Rev. AApril 6, 2009, Released Page 131