Grass Valley PDR 200 Service Manual - Manual (Page 38)

Chapter 3 Theory of Operation
3-6 PDR 200 Service Manual
Specific Boards
The specific boards discussed below are:
• Mother Board.
• Reference Genlock.
• Master and Slave Enhanced Disk Recorder.
• PCI Board
• ASPB
• Fibre Channel
• Mix Effects
Mother Board
This mother board provides three main functions:
• Power supply distribution for the plug in circuit boards.
• The EISA bus for program control for the PDR200.
• The video bus, or router, to move the parallel digital video signal through the
Profile.
EISA Bus
The EISA bus interconnects all 17 plug-in circuit board slots. Slot 2 is an ISA-only
slot used for the VGA Interface board and Slot 1 is dedicated to the system processor
board. The system processor communicates with all plug-in circuit boards, including
the ISA board over the EISA bus, which is ISA-compatible.
Video Bus
The Video Bus is not a bus in the usual sense. It provides a common set of connectors
into and out of the Video Router. Each connector is physically limited to four inputs
and four outputs, with the exception of Slots 6 and 7, which have six inputs and two
outputs. Most of the plug-in circuit boards do not require all four inputs and outputs.
However, in some cases more than four inputs or outputs may be required. In those
cases, inputs or outputs from adjacent slots are borrowed.
Each of the 12 video slots (J05 - J16) has a 96-pin Dual-In-Line (DIN) connector.
Each connector has eight, 8-bit router interfaces. In all but slots 6 and 7, these are
divided into A through D as inputs from the router, and E through H as outputs to the
router. For slots 6 and 7 only, G and H are also used as inputs from the router. Clock
signals are also routed to each of the 12 connectors.
The Video Router is a 32-by-32 cross-point video switch. The video data paths, 8-bits
wide, conform with CCIR-601. The router connects video data from an I/O to the
EDR circuitry and back. Mix Effects provides additional video manipulation.