Grass Valley PDR 200 Service Manual - Manual (Page 40)

Chapter 3 Theory of Operation
3-8 PDR 200 Service Manual
Master Enhanced Disk Recorder
The Master Enhanced Disk Recorder (MEDR) is a 7-inch high EISA compatible
board with two real time video compression/decompression channels (JPEG
channels). It implements a field-at-a-time JPEG compression/decompression
algorithm, two differential Ultra-SCSI interfaces, a Real Time (control) Processor
(RTP), a 32-bit EISA Bus Master and Slave interface, and an intra-board 32-bit, 33
MHz Global Peripheral Component Interconnect (GPCI) bus interface.
Connection of the MEDR board to an optional Slave Enhanced Disk Recorder
(SEDR) board adds two more JPEG channels and two SCSI channels. Figure 3-3
shows a block diagram of how a set of EDR boards (Master and Slave) and a Fibre
Channel board interconnect in a Profile system.
Figure 3-3. Block Diagram - Profile EDRs and Fibre Channel
NT
Proces-
EISA
Bridge
NT
DRAM
NT System
Processor
Fibre
Channel
EISA
Bridge
EISA
Bridge
Local/
IBus
DEC2115
2
JPEG
PCI9060
ES
RTP
i960H
RAM
Controller
& Arbiter
EDO
DRAM
SRAM
PCI9060
ES
Ch. A
CO-
Ch. A
RAM
Ch. B
RAM
Ch. B
CO-
SCSI A
SCSI B
Arbiter
Local/
IBus
DEC2115
2
JPEG
Ch. A
CO-
Ch. A
RAM
Ch. B
RAM
Ch. B
CO-
SCSI A
SCSI B
Arbiter
L
P
C
I
B
u
s
L
P
C
I
B
u
s
R
T
P
B
u
s
Master EDR Slave EDR
EISA
CPU