Aeroflex Circuit Technology

SCD7005 REV B 8/2/01

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15

Bit

Name

Function

7

BUSY BIT

RTU BUSY

HIGH- BUSY

LOW - NOT BUSY

MASTER RESET SETS BIT HIGH

8RT/BC

Remote Terminal/Bus Controller Bit. This line, when set HIGH, causes the hybrid

to function as a Remote Terminal. When set LOW, it will function as a Bus

Controller. Master Reset sets this bit HIGH

9

Transaction/

Test

Transaction/Test Mode Bit. When this bit is set high, normal transactions will be

handled, eg., BC to RT, RT to BC, RT to RT. If this bit is set low and a trigger

transaction is issued, the self-test will be performed for the MIL-STD-1553

protocol chip.

10

LT Local

Loop Test Local Bit (Used in conjunction with BIT 9). This signal selects the self

test path. When set LOW, the internal digital path is selected. When set HIGH,

the external path, including transceivers, is selected.

11

Bus Select

Bus Select (Bus Controller Only). When set high, Bus 1 is selected. When set

LOW, Bus 0 is selected.

12

Normal/RT-RT

Normal/Remote Terminal-Remote Terminal Bit. When set HIGH, BC to RT and

RT to BC transfers are performed. When set LOW RT to RT transfers are

performed. Two command words are required and two returned status words will

be expected.

13

SERV REQ/

Auto-Retry

(LSB)

Service Request/Auto-Retry (LSB) Bit.

RT MODE: A LOW in this bit will cause the service request

bit in the status word to be set.

BC MODE: This is the LSB of the Auto-Retry options. See

table on this page, Bit 14

14

SERR

Auto-Retry

(MSB)

Subsystem Error/Auto-Retry (MSB) Bit.

RT MODE:

A LOW in this bit will cause a Subsystem Error

Bit in the status word to be set.

BC MODE:

This is the MSB of the Auto-Retry option

15

DBCACC/

Auto-Retry

Other Bus

Dynamic Bus Control Accept/Auto-Retry Bus Bit.

RT MODE: This bit should be LOW if the subsystem is able to accept

control of the bus, if offered.

BC MODE: This bit should be HIGH if an invalid transfer is to be

retried according to the selected auto-retry option listed

above.

Table 7 – Operational Register (continued)

AUTO-RETRY OPERATIONS

Options selected:

Auto-Retry Other Bus

Bit 15

Bit 14

Bit 13

0

1

0

0

No Retry

No Retry

01

P

S

10

P/P

P/S

11

P/P/P

P/S/S