Spectral Instruments Series 800, User Manual, Page: 62 / 70

Spectral Instruments
Pt # 2500- 62
C or D flips the image right-to left. Re-orienting the image must be handled by your
software if the origin of the image and its mapping to the application is important.
Over-Scan in Multi-Port CCD Readout
Using the 4-port model, you can have post-scan but your display software must deal
with the result. All of the pre-scans and pre-extensions are available (as long as you
are content with them being in all four quadrants identically. There is no post mask.
Post scan can occur in both directions. Some idiosyncrasies occur as different
vendors handle the split parallel and serial registers. These are handled in the
specific DSP firmware. This firmware is specific to the CCD being read out multi-
port. Buried within this firmware are the mechanisms required to handle the
idiosyncrasies.
The configuration parameters include several that are related to multi-port operation
of the camera. When single port readout is selected, the serial registers shift toward
A and D when the serial phasing parameter is set to 0. They shift to B and C when
this parameter is set to 1. Similarly, when single port readout is selected the parallel
register shifts toward the A-B side, labeled SR1 in Figure B1 below. When the
parallel phasing parameter is set to 1 the parallel register reverses shift direction
toward SR2.
When two-port readout is selected, it is usually the case that the serial register is
split. For this situation the serial phasing parameter must be set to 0 and the serial
split set to one. If the serial phasing parameter is set to 1 for two-port readout the
serial direction reverses and the registers shift toward the center. This produces no
image at all.
When four-port readout is selected, the presumption is that both the parallel and
serial registers are split. For this situation the parallel phasing parameter must be set
to 0 and the serial phasing parameter must be set to 0. This leaves the left and right
sides shifting toward SR1 and SR2 respectively and the serial registers shifting
toward their respective output port. If the parallel phasing parameter is set to 1 for
four-port readout the parallel direction reverses and the registers shift toward the
center. Similarly, if the serial phasing parameter is set to 1 for four-port readout the
serial registers shift away from their respective output nodes. Either of these
situations produces no image at all.