Pin Description
Signal
Direction
Pin
Signal Description
INPUT
K6,K5
J5,H5
F4
RTAD 0-4
RT address lines - These should be hardwired by the user.
RTAD4 is the most significant bit.
INPUT
INPUT
J6
RTADPAR
RT address parity line - This must be hardwired by the user to
give odd parity.
J4
BIT DECODE
Bitword Decode - When held low, prevents resetting TXTO Bit,
HSFAIL Bit, and LTFAIL Bit in the BIT Word (as well as TF and
SSF Bits in the Status Word) upon receipt of a Transmit Bit
Word Mode Command.
INPUT
INPUT
F5
G5
E4
BCSTEN 1
BCSTEN 0
6MCK (Clock)
Broadcast command enable Bus 1 - When low the
recognition of broadcast command is prevented on Bus 1.
Broadcast command enable Bus 0 - When low the
recognition of broadcast command is prevented on Bus 0.
INPUT
BIDIR
6 Megahertz master clock.
E9
D6
D7
A9
D8
B9
D9
C9
IH 08 (LSB)
IH 19
Internal Highway - Bi-directional 8 bit highway on which 16 bit
words are passed in two bytes. IH 715 is the most significant bit
of each byte, the most significant byte being transferred first.
The highway should only be driven by the subsystem when data
is to be transferred to the RT.
IH 210
IH 311
IH 412
IH 513
IH614
IH715 (MSB)
OUTPUT
K10
DTRQ
Data Transfer Request - Goes low to request a data transfer
between the ASIC and subsystem. Goes high at the end of the
transfer.
INPUT
F6
G6
J9
DTAK
IUSTB
H/L
Data Transfer Acknowledge - Goes low to indicate that the
subsystem is ready for the data transfer.
OUTPUT
OUTPUT
OUTPUT
Interface Unit Strobe - This is a double pulse strobe used to
transfer the two bytes of data
High/Low - Indicates which byte of data is on the internal
highway. Logic level "0" for least significant byte.
J7
GBR
Good Block Received - Pulses low for 500ns when a block of
data has been received by the ASIC and has passed all the
validity and error checks.
OUTPUT
INPUT
G9
E8
NBGT
New Bus Grant - Pulses low whenever a new command is
accepted by the ASIC.
MEREQ
Message Error Request - Positive-going edge will cause
Message Error Bit in Status Word to be set.
12
Aeroflex Circuit Technology
SCD3492 REV B 6/26/01 Plainview NY (516) 694-6700
AEROFLEX [ AEROFLEX CIRCUIT TECHNOLOGY ]
