RX

CMD

DATA DATA

DATA

*

STATUS

TX

CMD

DATA DATA

DATA

DBC

CMD

10

SCDCT2578 REV B 3/11/98

Error Conditions

Action taken by device

Error Conditions

Action taken by device

1. Invalid command.

No response.

Command ignored.

2. Non contiguous

No status response.

command words.

Set message error.

Sequence terminated.

3. Transmit command

No status response.

followed by another word

Set message error.

(excluding command

Sequence terminated.

word for RTA, in which

case it will respond to

the latest command).

4. Transmitting terminal

No status response.

does not respond with

Set message error.

status within 16 uS.

Sequence terminated.

5. Incorrect terminal

No status response.

transmitting.

Set message error.

Sequence terminated.

6. Non contiguous data

No status response.

following status from

Set message error.

RTB.

Sequence terminated

equal to receive word

Set message error.

7. Invalid data transmitted

No status response.

from RTB.

Set message error.

Sequence terminated.

8. Too few or too many

No status response.

data words.

Set message error.

Sequence terminated.

WRAP AROUND

The wrap around capability is for test purposes only. It will test for

transfers to and from the Bus Controller without any sub system

intervention.

The wrap around sequence will commence on receipt of a valid

receive command word containing the wrap around subaddress

(1E) providing the WRAPEN input is set high. The data received

is stored in the data buffer memory and the device will respond

with status. The Bus Controller will then send a transmit command

to subaddress 1E and the data contained in the memory will be

transmitted following the status.

For the test to operate correctly the number of data words to be

transmitted must be the same as the number received.

1. Invalid receive command.

No response.

Command ignored.

2. Invalid data word.

No status response.

Set message error.

Sequence terminated.

3. Non contiguous data.

No status response.

Set message error.

Sequence terminated.

4. Too few or too many

No status response.

data words.

Set message error.

Sequence terminated

5. Invalid transmit

No response.

command.

Command ignored.

6. Transmit command

No status response.

followed by another

Set message error.

word.

Sequence terminated

7.Transmit Broadcast

No status response.

address.

Set message error.

Set broadcast.

Sequence terminated.

8. Transmit word count not

No data transmission.

count.

Sequence terminated.

DYNAMIC BUS CONTROL (00)

The device will respond with status.

Error Conditions

Action taken by device

1. Invalid command.

No response.

Command ignored.

2. Command followed by

No status response.

another word.

Set message error.

Sequence terminated.

3. T/R bit of command set

No status response.

to zero.

Set message error.

Sequence terminated

4. Broadcast address.

No status response.

Set message error.

Set broadcast.

Sequence terminated.

5. T/R bit of command set

No status response.

to zero and broadcast

Set message error.

address

Set broadcast.

Sequence terminated.