Sharp AR-P13 Service Manual page 98

The Printer Board is mainly composed of PowerPC 603e (U24) and Double Finger (U25).
The data bus in the Printer Board branches off to a local data bus and a system data bus. These are connected in alternating
connection with a Bus Transceiver.
The local data bus is a 64-bit data bus directly connected to the PowerPC 603e. Double Finger, SDRAM (U51,52), and SDRAM
DIMM are connected to this bus.
The system data bus is a 32-bit data bus connected to Program ROM SIMM, Parallel Controller (U26), PLD (U3), RECTOR
(U13) and the Print Server Card Interface (J2).
SDRAM and SDRAM DIMM are used as main memories for the system and are controlled by Double Finger.
Program ROM SIMM stores the operating programs of the system and some parts of the standard font data and is controlled
by Double Finger.
The Parallel Interface circuit is composed of Parallel Controller, Parallel Interface (J10), and other peripheral ICs, and controls
parallel communication with computers and operates the sending and receiving of print data, command signals and status
signals. The Parallel Interface is corresponding to Compatible mode, Nibble mode, and ECP mode in compliance with IEEE-
1284.
Engine Interface circuit is composed of the PLD, Engine Interface (J1,5) and other peripheral ICs, and it controls the PCI bus
communication with System Board installed in the machine itself and operates the sending and receiving of print data, com-
mand signals and status signals. The sending/receiving of print data, and command/status signals are operated in DMA
transfer.
EEPROM (U7) stores the setting information for the printer designated by the users and in controlled by the PLD.
The Compressing Data circuit is composed of the RECTOR (U13), and other peripheral ICs, and it converts the print data to LZ
format-compressed data.
The Print Server Card is composed of the Network Control IC and other peripheral ICs, and operates the transmitting of print data
and command/status signals through the Local Area Network.
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