HP LaserJet 4101mfp CPB terminology, Figure 21. Copy processor board components

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.

MIPS	SRAM	IEEE 1394 protocol chip	FPGA	DSP RAM
processor

DSP

ASIC

16-MB DIMM

Firmware code

DIMM

		Hard
IEEE 1394 phy.	PCI	code for
	bridge	FPGA

Figure 21. Copy processor board components

C9148-90909 5 Theory of operation 57