NEC NP-NC900C-A, Руководство по обслуживанию

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11-3
CIRCUIT DESCRIPTION
“Confidential, Do Not Duplicate without written authorization from NEC.”
3. LAN
The RTL8100CL (IC7101) is an Ethernet controller with the respective functions of Ethernet MAC, PHY, and
Transceiver applicable to 10Mbps, 100Mbps operation.
External projector control and setup are carried out via the LAN.
The CPU functions as a host device and ASSIST3 provides a bridge of CPU bus and PCI bus, and transfers
data to the RTL8100CL (IC7101).
The differential data modulated by the RTL8100CL pass through the transformer (T7100) and are sent from
the RJ-45 connector (M6003) on the Mother PWB to the outside and other boards via the router.
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Power
The CPU operates on the two types of power supplies specified below.
I/O : 3.3V
Core : 2.5V Stepped down from 3.3V (P3P3V) through the Series Regulator (PQ070XZ01ZP @IC7102).
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PROM
BR93L46RF(IC7103) is a 64*16-bit EEPROM where the MAX address, ID parameter, etc., are saved.
4. External Interface Port
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GPIO M7001 (D-Sub 37pin)
Used for power sequence and signal changeover for the projector.
Input : #5 - #8, #24 - #27
The data level is converted at the photo coupler (IC7205 – 7208) and the input data are entered
in the CPU via the buffer (IC7214).
#3, 4, 22, 23 are connected to ICP.
Output : #13 - #18, #32 - #35
The photo coupler (IC7201 – 7204) is driven from the CPU via the buffer (IC7214).
#9, 12, 28, 31 are connected to ICP.
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3D M7005 (D-Sub 15pin)
3D Control
Level conversion is performed by the SW (IC7215, 7216) and the buffer (IC7213, 7217) under the control
from the ICP and CPU.
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RS232 M7002 (D-Sub 9pin)
Used for projector control from external equipment.
Controlled by the CPU via the transceiver (AD3202 IC7218).
Otherwise, the 232C line of the 3D Ctl Port is connected to the CPU via another channel of the same
device.
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USB M7000
Controlled by the CPU via the transformer T7101.
LM3525 (IC7110) is the Power SW (+5V) of the USB Port and controlled by the CPU.
This device has a protective circuit. It suspends the supply of power when the output current exceeds 1A.
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Remote control M7003 (Mini Jack)
This connector receives a +5Vp-p signal input from the remote controller through cables.
Waveforms are trimmed by the FET (Q7103, 7104) and the processed signal is fed to the ASSIST3 after
level conversion (3.3Vp-p).
The ASSIST3 decodes this signal and the resultant remote control input is sent to the CPU.
IC7102 (PQ070XZ01) supplies the power for remote control drive.
The output from this device is maintained at approxi4.0V so that +3.3V can be maintained on the
remote control side in the case of 16m cable connections.