Aeroflex Circuit Technology

SCDCT1995 REV A 11/21/01 Plainview NY (516) 694-6700

9

DWSYNC

SOURCE

Data Word Sync - This line goes low if a data word sync and two Manchester

biphase bits are valid.

CMSYNC

SOURCE

Command Word Sync - This line goes low if a command word sync and two

Manchester biphase bits are valid.

NDRQ

SOURCE

No Data Required - This line goes low if the encoder transmit buffer is full i.e.

another word is going to be transmitted. This signal is for information only and

must not be used to enable data from the subsystem.

PASMON

SINK

Passive Monitor - When functioning as a Bus Controller this line acts as a

passive monitor select. The active going edge of this line will cause the

REQBUS lines to be latched and that bus, now selected will be monitored so

long as PASMON remains low. All traffic on the bus will be handed, after

validation, to the subsystem via STATSTB for status and commands words,

and RMDSTB for data words.

BCOPSTB

SINK

Bus Controller Operation Strobe - When functioning as a Bus Controller a

low going pulse on this line will initiate the selected bus controller operation on

the requested bus, using BCOPA&B and REQBUSA&B.

BCOPA

SINK

Bus Control Operation A - Least significant bit of the bus controller operation

select lines.

BCOPB

SINK

Bus Control Operation B - Most significant bit of the bus controller operation

select lines.

REQBUS A

SINK/SOURCE

Request Bus A - This line,wwhen in RT mode, is the least significant bit of the

bus request lines which specify the origin of the command, ie. they are

sources. When in BC mode these lines are sinks and specify which bus is to be

used for the next command.

REQBUS B

SINK/SOURCE

Request Bus B - Most significant bit of the bus request lines. (See above for

description.)

RT/BC

SINK

Remote Terminal/Bus Control - This line when high causes the ASIC to

function as a remote terminal. When low the ASIC functions as a bus controller

or passive monitor.

DBCACC

SINK

Dynamic Bus Control Accept - This line should be permanently tied low if a

subsystem is able to accept control of the bus if offered.

LTFAIL

SOURCE

Loop Test Fail - This line goes low if any error in the transmitted waveform is

detected or if any parity error in the hardwired RT address is detected.

ERROR

SOURCE

Error - This line latches low if a Manchester or parity error is detected. It is

reset by the next CMSYNC (RT mode) and also by RTO in the BC mode.

RTO

SOURCE

Reply Time Out - This signal will pulse low whenever the reply time for a

transmitting terminal has been exceeded. This line is intended for the bus

controller use.

TXTO

SOURCE

Transmitter Time Out - This line goes true if the transmitter time out limits are

exceeded.

PARER

SOURCE

Parity Error - This line will pulse low if a parity error is detected by the

decoder.

MANER

SOURCE

Manchester Error - This line will pulse low if a Manchester error is detected by

the decoder.

Pin Description (Cont.)

Signal

Hybrid

Sink or Source

Signal Description