Nortel Networks 553-3001-211 manual Esdi card block diagram, Ram

Page 842 of 894 QPC513 Enhanced Serial Data Interface card

Functional description

The QPC513 ESDI card is an intelligent, two-port synchronous serial data interface card. See Figure 180. 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).

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.

Figure 180

ESDI card block diagram

	Address	Local bus
System	bus
	Data
processor		System
	bus
bus		bus
	Control	interface
	bus

DMA

channel

1

ESDI card

local

processor

DMA

channel

2

EPROM

System

and

cache

RAM

Baud rate generator 1

Synchronous
serial channel
1	1
Synchronous
serial channel
2	2

Baud rate generator

2

553-AAA1159

Port 1

Line (J1) interface

Line	Port 2
interface	(J2)

553-3001-211 Standard 2.00 September 2004