FIC M296 - Manual (Page 117)

Hardware Functional Overview
4.15 Power Subsystem
The Power Subsystem consists of the following major sections:
4.15.1 AC Power Adapter
The computer is equipped with a 60W universal AC power adapter that converts AC voltage
(100 to 240VAC, 50 to 60Hz) into DC voltage used to operate the notebook and charge the
batteries.
4.15.2 Internal Battery Pack
The computer utilizes Lithium-Ion (Li-Ion) that provides DC power for the notebook and real
time clock battery on the motherboard when the AC Adapter is not connected to the
computer.
The normal charging time for the battery is around 2.5 hours when computer is turn off while
it should take around 8 hours when the computer is running. Running time of battery is
around 2 to 2.5 hours.
4.15.3 DC-DC Module of Motherboard
The DC-DC module receives approximately 12VDC from the battery pack and uses this input
voltage to generate multiple regulated output voltages to provide power for all internal
notebook board assemblies.
4.15.4 LCD Inverter Board Assembly
The LCD Inverter Board Assembly is located in the LCD Panel Assembly. It converts the
+12VDC input directly from the Battery Pack into a high voltage AC output used to light the
CCFT (Cold-Cathode Fluorescent Tube).
4.16 Micro-P Subsystem (PMU-08)
The micro controller Mitsubishi PMU08 acts as a supplement for the power management
control. It supports many functions via the SMBus interface.
The system communicates with the PMU08 via the SMBus interface. The SMBus host
(M38869) should be first initialized before starting the transaction. The following is the
procedure for system communication with PMU08:
1. Enable SMBus interface by writing 01h to SmbHstCfg register.
2. Get SMBus I/O port base address by reading from SmbBA register.
3. Clear SMBus status by writing 1Eh to SmbHstSts register.
4. Write the PMU07 slave address to SmbHstAdd register.
− Send command to PMU08 -- Slave address is 04h.
− Read data from PMU08 -- Slave address is 05h.
5. Write the desired command to SmbHstCmd register.
6. Write the desired parameters to SmbHstDat0 (High byte) and SmbHstDat1 (Low
byte) registers if the system wants to send command to PMU08.
7. Wait for SMBus interrupt occurred by monitoring SmbHstSts register INTR bit.
8. Get the desired data by reading from SmbHstDat0 (High byte) and SmbHstDat1
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FIC M295 / M296 Service Manual