C9148-90909 5 Theory of operation 57
Copy processor board
This section describes the operation of the copy processor board (CPB) during normal operation
of the MFP. This description is more detailed than the CPB troubleshooting chapter in this
manual.
The CPB is the link between the formatter in the print unit and the scanner controller board in the
scan unit. Control signals from the formatter are sent to the CPB. The CPB then sends these
control signals to the scanner controller board. After the scanner controller board completes the
scanning process, the scanned data is sent to the copy processor board. The copy processor
board processes the image and sends the image data to the formatter.
CPB terminology
● ASIC (application specific integrated circuit): is the system controller that provides the
peripheral component interconnect (PCI), DIMM, and processor interface. The ASIC
performs monochrome data compression.
● Firmware code DIMM (dual inline memory module): contains the firmware that controls the
system.
● Digital signal processor (DSP): runs the image processing algorithms.
● FPGA (field programmable gate array): provides an interface to the scanner, SRAM, DSP,
and PCI bridge and provides front-end image processing.
● IEEE 1394 phy. (physical layer): provides an interface from the CPB to the formatter (high-
speed copy connect cable)
● IEEE 1394 protocol chip: connects the PCI bus to the IEEE 1394 phy.
● MIPS (millions of instructions per second) processor: is the system processor that runs the
firmware.
● PCI (peripheral component interconnect) bridge: connects the PCI bus to the FPGA.
● RAM (random access memory) DIMM: provides main system memory and temporary
storage for image data and firmware variables.
● RAM for DSP: provides temporary storage for image processing in the DSP.
● SRAM (static RAM): is the memory used for aligning the image data from the scanner.
Figure 21. Copy processor board components
PCI
bridge
Hard
code for
FPGA
IEEE 1394 protocol chip
IEEE 1394 phy.
Firmware
code
DIMM
16-MB
DIMM
ASIC
MIPS
processor
SRAM FPGA DSP RAM
DSP
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