
Hardware Description
3-34
Copyright © ARM Limited 2000. All rights reserved.
appear through the keyboard housing. Each two LEDs are wired in parallel on when the
distribution board is attached. The port assignments of the LEDs are shown in Table
3-16.
The LEDs can be assigned to any function by the system developer. For example, they
could be used to provide keyboard indicators, such as CapsLock and NumLock. The
status of these indicators is under software control and is not automatically set by the
keyboard controller.
The LEDs can be either on, off or blinking. To minimize power, it is recommended that
the LEDs are set to blink on and off. In this mode, the on and off periods can be
controlled in units of 1/16 of a second. Faster blink rates give the LED the appearance
of being illuminated continuously. The LEDs can be made to flash by adding meta blink
intervals within blink cycle. This give the appearance of the LED flashing.
For information about programming the LEDs, see Programming the keyboard
controller on page 4-20.
Note
You cannot put the keyboard controller into SUSPEND mode if a LED is on or is
blinking, so care should be taken in the use of the LEDs.
3.9.3
Switch sensing with the keyboard controller
The P1100 provides a number of switches that can be read from keyboard controller
internal registers:
•
DIL (three switches from a bank of five)
•
hexadecimal rotary switch
•
external switch (wired through JP11)
•
lid switch (wired through JP9)
Table 3-16 Keyboard controller GPIO/LED assignment
Port Name
LED
GIO00/LED0
KBD_LED0 – red
GIO01/LED1
KBD_LED1 – yellow
GIO02/LED2
KBD_LED2 – green
GIO03/LED3
KBD_LED3 – green
Summary of Contents for Prospector P1100
Page 1: ...ARM DUI 0122A Prospector P1100 User Guide ...
Page 4: ...iv Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Page 86: ...Hardware Description 3 54 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...
Page 140: ...Connector reference A 18 Copyright ARM Limited 2000 All rights reserved ARM DUI 0122A ...