Difference between revisions of "84PCE:Ports:A000"

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(Synopsis)
Line 4: Line 4:
 
'''Port Number:''' A000-A003
 
'''Port Number:''' A000-A003
  
'''Memory-mapped address:''' F50000
+
'''Memory-mapped address:''' F50000-F50003
  
 
'''Function:''' Set the mode of the keypad controller
 
'''Function:''' Set the mode of the keypad controller

Revision as of 02:29, 31 March 2015

Synopsis

Port Number: A000-A003

Memory-mapped address: F50000-F50003

Function: Set the mode of the keypad controller

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