84PCE:Ports:A000

Synopsis

Port Number: A000-?

Memory-mapped address: F50000-?

Function: Set the mode of the keypad controller

F50000 (R/W):

Bits 0-1: Scan mode

• Mode 0: Idle.

• Mode 1: Indiscriminate key detection. Data registers are not updated, but whenever any key is pressed, interrupt bit 2 is set (and cannot be cleared until the key is released).

• Mode 2: Single scan. The keypad is scanned once, and then the mode returns to 0.

• Mode 3: Continuous scan. When scanning completes, it just starts over again after a delay.

Bits 2-15: Number of APB cycles to wait before scanning each row

Bits 16-31: Number of APB cycles to wait between scans

F50004 (R/W): Bits 0-7: Number of rows to read (later rows are not updated in F50010-F5002F, and just read as whatever they were before being disabled)

Bits 8-15: Number of columns to read (later column bits in a row are set to 1 when it is updated)

F50008 (R/W): Keypad interrupt status/acknowledge (3-bit). Write "1" bits to acknowledge.

• Bit 0: Keypad scan complete

• Bit 1: Keypad data register changed

• Bit 2: Key pressed in mode 1

F5000C (R/W): Keypad interrupt mask (3-bit). Set each bit to 1 if the corresponding event in [F50008] should cause an interrupt.

F50010-F5002F (R): Keypad data, one halfword per row.

F50030-F5003F (R/W): Keypad GPIOs. Each register is 20 bits, with one bit per GPIO. The role of each register is unknown.