VV0670P001 View Datasheet(PDF) - Vision
Part Name
Description
MFG CO.
'VV0670P001' PDF : 36 Pages View PDF
Colour Processor Interface ASIC
2.2.6 Control Processor
2.2.6.19 Control Processor Interfaces
As shown in figure 2.16 below, the Control Processor uses five main interfaces to control the operation of the
CPiA device:
• VP Control Registers
• VP Frame Start Interrupt
• VC Control Registers i.e. PP, USB interfaces, Compression Control and DRAM Interface
• USB_BANDWIDTH, ID_SELECT and DEBUG input pins
• UART serial comms (debug output only)
Figure 2.20 : Control Processor Interfaces
Video Compressor
Parallel Port Interface
Video Proccessor
Frame
Start
Interrupt
Control Processor
USB Interface
Image Capture /
Compression
USB_BANDWIDTH
ID_SELECT
DEBUG
Serial UART
DRAM Interface
System DRAM
The VP Control Registers are used to control the colour processing of the raw sensor data. Colour channel
gains, colour saturation and contrast values are all applied by the VP module. Also, communications to the
sensor, for control of exposure time and gain, are done via the VP module.
The VP Frame Start interrupt is used to trigger Exposure Control and Auto White Balance algorithms that run
on the Control Processor.
The VC Registers are used to control the host interfaces (both Parallel Port and USB) and the image capture
/ compression / upload processes. In addition access to the DRAM, used to store the frameheader, and
during self-test mode, is via the VC regisiters. Control of transitions between the system power states of the
camera is preformed via VC registers that access the Power Managment module.
The USB_BANDWIDTH, ID_SELECT and DEBUG inputs go directly to port pins on the embedded Control
Processor core and modify the several aspects of the camera behaviour. In normal operation these three
inputs should be left unconnected (internally pulled up).
The USB_BANDWIDTH input can be used to select an alternate set of isochronous bandwidths for the USB
interface. See the USB Interface section of this document for more details.
The ID_SELECT input is used to select a Device ID (Parallel Port interface) or Product ID (USB interface)
that is used for combined USB and Parallel Port cameras. If held LO it causes a different 1284 Device ID to
be returned on the parallel port interface, and a different USB Product ID on the USB Interface.
The DEBUG input if pulled LO will cause the Control Processor to send diagnostic output to the serial UART.
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02/07/98
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