Nortel Networks Circuit Card User Manual
Page 854 of 906
QPC513 Enhanced Serial Data Interface card
Functional description
The QPC513 ESDI card is an intelligent, two-port synchronous serial data
interface card. See Figure 183. The two serial input/output data ports
terminate on DB-25 connectors on the front panel of the card.
interface card. See Figure 183. The two serial input/output data ports
terminate on DB-25 connectors on the front panel of the card.
Each port operates independently in synchronous mode, in half or full duplex,
at speeds of up to 64 kbps. Each port can be connected to either Data Terminal
Equipment (DTE) or Data Communications Equipment (DCE).
at speeds of up to 64 kbps. Each port can be connected to either Data Terminal
Equipment (DTE) or Data Communications Equipment (DCE).
The electrical interface for the ESDI card may be either EIA RS-232-C or a
proprietary high-speed interface. The high-speed interface combines features
of RS-422-A for data and timing signals with features of RS-232-C for
control signals.
proprietary high-speed interface. The high-speed interface combines features
of RS-422-A for data and timing signals with features of RS-232-C for
control signals.
Figure 183
ESDI card block diagram
ESDI card block diagram
Address
bus
bus
Data
bus
bus
Control
bus
bus
System
processor
bus
Local bus
Baud rate
generator
generator
1
System
bus
interface
ESDI card
local
processor
EPROM
System
and
cache
RAM
DMA
channel
1
Synchronous
serial channel
1
Line
interface
1
Port 1
(J1)
Baud rate
generator
generator
2
DMA
channel
2
Synchronous
serial channel
2
Line
interface
2
Port 2
(J2)
553-AAA1159