Aeroflex Circuit Technology

SCD7005 REV B 8/2/01

Plainview NY (516) 694-6700

13

Name

Use

INT #1

GOOD BLOCK (RT)

Indicates reception of a valid block of data. The RECEIVE COMMAND WORD

is loaded in RCV CMD WD Register. This interrupt is issued after the new

block of data is moved into the Internal RAM.

VALID (BC)

Indicates that the Bus Controller has initiated and observed a valid message

transfer on the 1553 data bus.

INT #2

VALID TRANS (RT)

Indicates reception of a valid TRANSMIT COMMAND WORD. The

TRANSMIT COMMAND WORD is loaded in CMD WD Register. Note: This

interrupt does not necessarily indicate that the transmitted data was received

by the bus controller.

INVALID (BC)

Indicates that the Bus Controller has initiated a message transfer on the data

bus, but the message traffic has been deemed invalid.

SYNC NO DATA

Indicates reception of a valid mode command SYNCHRONIZE WITHOUT

DATA

SYNC W/DATA

Indicates reception of a valid mode command SYNCHRONIZE WITH DATA.

The synchronize data word is loaded into the SYNC/STAT WD #2/RMD

REGISTER. This interrupt will not be issued if a word count high or low error

occurs.

DONE

This interrupt is issued in response to an I/0 command from the subsystem. In

response to an I/0 load OUTPUT buffer command, it indicates that the

complete 32 word message block (SUBADDRESS) has been loaded into the

OUTPUT FIFO buffer. In response to an I/0 load internal RAM from INPUT

FIFO buffer command, it indicates the full message (1 to 32 WORDS) has

been loaded.

TIMING

a. In response to an I/0 load OUTPUT buffer: 16.5 to 33 µsec.*

b. In response to an I/0 load RAM from INPUT buffer: 16.5 to 33 µsec for 32

WORDS*, for SHORTER LOAD OPERATIONS SUBTRACT 0.5 µsec per

(16 bit) word, i.e., 17 µsec to 0.5 µsec for single word.

*NOTE:

In the unusual case where a superceding transmit command on the redundant

bus occurs at the returned status time for a valid 32 word receive,

simultaneously with an I/0 transfer request, the DONE interrupt may be

delayed for an additional 16.5 usec.

BUFF EF

This flag may be used to speed up read data operation in response to an I/0

load OUTPUT FIFO buffer command. The BUFF EF flag will go high when the

first word is loaded into the OUTPUT FIFO buffer. The word may be read at

that time. Please see Figure 6.

MODERESET

Indicates reception of a valid RESET mode command.

Table 6 – Discrete Interrupts Summary