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Hardware Description
Copyright © ARM Limited 2000. All rights reserved.
3-49
3.15.5
Power management
The P1100 has three operating modes:
Normal mode
The system is fully operational. For module-only variants, all the
LCD supplies can be permanently powered off.
Configurations with keyboards and LCDs need to enable the
LCD_OUT2
LCD supply and, for transmissive displays with
backlight, the
LCD_OUT3
inverter supply.
Idle mode
Used when the case is open and the system is waiting for a
keyboard event. The LCD must be refreshed, and all the
peripherals capable of bringing the machine out of IDLE must be
configured to generate an interrupt. This is primarily the keyboard
controller and touchscreen, but can also include the serial ports
and IrDA interfaces. Any power-saving is limited in this mode
because the DRAM and SA-1100 core must remain active to
allow screen-refresh to continue.
Sleep mode
Used when the case is closed or no activity detected for a
predetermined period of time. In this mode the screen and the
SA-1100 core are powered down. The system consumes as little
power as possible.
Entering sleep mode
To enter sleep mode the following steps should be taken:
1.
Turn off LCD
2.
Turn off LCD power supply
3.
Disable the LCD controller
4.
Turn off all other supplies
5.
Enable wake-up keys on the keyboard controller.
6.
Flush SA-1100 Dcaches and save the processor context into memory
7.
Place DRAMs into self refresh mode
8.
Place the SA-1100 into sleep mode
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 ...