Each CCD camera is controlled from a host PC, which has software which allows it to set the parameters for the CCD and to accept the digitized data. The control commands and the CCD data are transferred on a bidirectional serial link to/from a PCI card in the host computer. The operating system for the host PC is either DOS, or a version of Linux (currently 2.6.x kernel drivers).
PCI Interface pcb block diagram
The PCI card has both a serial link (20Mbps) and an optical link (80 Mbps, not shown in block diagram). Either one or the other is configured using an on-board jumper. Both are full-duplex, with upstream and downstream word size of 16-bits. The downlink involves a serial to parallel conversion, and a 16K-word deep FIFO. The uplink involves a parallel-to-serial conversion.
The PCI card is built around an AMCC S5920 interface chip, which bridges the PCI bus to a local bus. The serial link hardware is attached to the local bus (also called the passthru bus or add-on bus).
S5920 Pass-thru block diagram
PCI Interface board
Greg Burley (burley@obs.carnegiescience.edu)
Ian Thompson (ian@obs.carnegiescience.edu)