
Hardware Description
Copyright © ARM Limited 2000. All rights reserved.
3-47
Battery backup
The P1100 provides a backup capacitor that powers the system for a short while if
neither the battery supply or external supply connected. This is a 1Farad SuperCAP,
designed to provide power for a short duration while the batteries are being changed. It
is designed to supply minimal power, with the system in sleep mode with DRAM in self
refresh, for around 1 minute maximum. The backup is charged from the battery.
3.15.3
Internal power distribution
The power supply subsystem outputs are summarized in Table 3-22 on page 3-47.
Table 3-22 Power supply rail usage
Name
Switched
Source
Usage
3V_SUPPLY
No
Linear regulator U37 and
PSU_+1V5
Yes
MAX1703 from 3V_SUPPLY
using the gain block in the
MAX1703 and P-channel MOSFET
Q3 as a linear regulator.
+1.5V to the SA-1100 core. Switched by
the SA-1100 when the +3V rail is stable.
CPU_PWR_EN is used to switch the
supply on using a FMMT617 transistor.
+3V
No
MAX1703 from 3V_SUPPLY.
+3V main system power, including
SA-1100 input/output pad voltage.
LCD_OUT1
Yes
MAX1703 from 3V_SUPPLY.
A switched version of +3V controlled by
the PLD_S1_OFF bit in the PLD power
control register.
LCD_OUT2
Yes
MAX863 from 3V_SUPPLY.
Used to supply the LCDs, a +3V3
controlled by the PLD_S2_ON bit in the
PLD power control register.
+5VO
No
Maxim MAX863 from
3V_SUPPLY.
Used to supply the LCDs, a +5V to the
StrataFlash and associated 74AHCT244
(U18) control buffer.
LCD_OUT3
Yes
External power supply.
+9V used to power the backlight inverter in
a transmissive color LCD configuration.
Controlled by the PLD_S3_ON bit in the
PLD power control register.
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 ...