AEROFLEX CT1999

CT1999
Remote Terminal and/or Bus Controller
for MIL-STD-1553B
Features
• Performs the Complete Dual-Redundant Remote Terminal and Bus Controller Protocol
Functions of MIL-STD-1553B
• Automatic Switchover to Superseding Input Commands
• MIL-PRF-38534 Compliant Circuits Available
• 750 mw Typical Power Consumption
• Small Size
• Available in Plug-in or Flatpack Configuration
CIRCUIT TECHNOLOGY
• Compatible with all ACT Driver/Receiver Units
www.aeroflex.com
• 5V DC Operation
• Direct replacement for CT1602
• Full Military (-55°C to +125°C) Temperature Range
General Description
The CT1999 design incorporates ASIC and five Octal Buffers that accomplish the dual redundant
MIL-STD1553B Remote Terminal and/or Bus Controller Protocol Functions. Buffering has been added to the
most commonly used output signals on the CT1999, minimizing external hardware requirements. The CT1999
connects directly to all ACT Driver/Receiver Units.
Block Diagram (With Transformer)
Encoder
Interface
Unit
SA & WC
Buffers
Internal
Highway
Buffer
BUS "0"
Discrete
Output
Buffers
Driver
Select
&
Enable
BUS "1"
Control
Data I/O
Decoder
"O"
T/R
Hybrid
T/R
Hybrid
Sub Address
&
Word Count
Outputs
Decoder
"1"
Buffered
Descrete
Outputs
Unbuffered
Outputs
Internal
Highway
Control
Control
Inputs
Terminal
Address
Inputs
ASIC
CT1999
eroflex Circuit Technology – Data Bus Modules For The Future SCDCT1999 REV B 8/14/01
Absolute Maximum Ratings
Parameter
Range
Units
Operating Free-air Temperature
-55°C to +125
°C
Storage Case Temperature
-65°C to +150
°C
Power Supply Voltage VCC
+7
Volts
Input Voltage
+7
Volts
Recommended Operating Conditions
Parameter
Min
Typ
Max
Unit
VCC Power Supply Voltage VCC
4.5
5.0
5.5
V
VIH High Level Input Voltage, Vcc = 5V
2.2
V
0.7
VIL Low Level Input Voltage, Vcc = 5V
V
Electrical Characteristics
(TA = -55°C to +125°C)
Parameter
VOH High Level Output Voltage
Test Conditions
Min
Max
Unit
Notes
IOH = -3mA
2.4
V
2B,5
IOH = -400µA
2.4
V
6
IOH = -800µA
2.4
V
7
VCC = 4.5V
VOL Low Level Output Voltage
IOL = +12mA
IOL = +4mA
0.4
V
2B,5
0.4
V
6
IOL = +2mA
0.4
V
7
-700
-200
µA
1
-20
20
µA
2A,2B
-700
-200
µA
3
-400
-25
µA
4
-900
-350
µA
1
-200
0
µA
2A,2B
-900
-350
µA
3
-500
-25
µA
4
285
mA
VCC = 4.5V
IIH High Level Input Current
IIL Low Level Input Current
ICC Supply Current
VCC = 5.5V, VIH = 2.4V
VCC = 5.5V, VIL = 0.4V
VCC = 5.5V
Notes (Pin numbers are for 90 pin Plug in package):
1. Pins 45 through 50 (RTADPAR,RTAD0,1,2,3,4). 2A. Pin 34 (IHDIR). 2B. Pins 37 through 44 (IH08 through
IH715). 3. Pins 24,36 (BUFINH, IHENA). 4. ALL remaining inputs ALL versions. 5. Pins 2 through 23 (Remaining
Buffered Outputs). 6. Pins 68,69,70,71 (TXINH0,TXINH1,TXDATA,TXDATA). 7. All remaining outputs.
Clock Requirements
Frequency
Stability (-55°C to +125°C)
Maximum Asymmetry
Rise/Fall Time
Aeroflex Circuit Technology
6MHz
±0.01%
48 - 52%
10ns MAX
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REMOTE TERMINAL OPERATION
Receive Data Operation
All valid data words associated with a valid receive data command word for the RT are passed to the subsystem. The
RT examines all command words from the bus and will respond to valid (i.e. correct Manchester, parity coding etc.)
commands which have the correct RT address (or broadcast address if the RT broadcast option is enabled). When the
data words are received, they are decoded and checked by the RT and, if valid, passed to the subsystem on a word by
word basis at 20 µs intervals. This applies to receive data words in both Bus Controller to RT and RT to RT messages.
When the RT detects that the message has finished, it checks that the correct number of words have been received
and if the message is fully valid, then a Good Block Received signal is sent to the subsystem, which must be used by
the subsystem as permission to use the data just received.
The subsystem must therefore have a temporary buffer store up to 32 words long into which these data words can be
placed. The Good Block Received signal will allow use of the buffer store data once the message has been validated.
If a block of data is not validated, then Good Block Received will not be generated. This may be caused by any sort of
message error or by a new valid command for the RT being received on another bus to which the RT must switch.
Transmit Data Operation
If the RT receives a valid transmit data command addressed to the RT, then the RT will request the data words from the
subsystem for transmission on a word by word basis. To allow maximum time for the subsystem to collect each data
word, the next word is requested by the RT as soon as the transmission of the current word has commenced.
It is essential that the subsystem should provide all the data words requested by the RT once a transmit sequence has
been accepted. Failure to do so will be classed by the RT as a subsystem failure and reported as such to the Bus
Controller.
Control of Data Transfers
This section describes the detailed operation of the data transfer mechanism between RT and subsystems. It covers
the operations of the signals DTRQ, DTAK, IUSTB, H/L, GBR, NBGT, TX/RX during receive data and transmit data
transfers.
Figure 7 shows the operation of the data handshaking signals during a receive command with two data words. When
the RT has fully checked the command word, NBGT is pulsed low, which can be used by the subsystem as an
initialization signal. TX/RX will be set low indicating a receive command. When the first data word has been fully
validated, DTRQ is set low. The subsystem must then reply within approximately 1.5 µs by setting DTAK low. This
indicates to the RT that the subsystem is ready to accept data The data word is then passed to the subsystem on the
internal highway IH08-IH715 in two bytes using IUSTB as a strobe signal and H/L as the byte indicator (high byte first
followed by low byte). Data is valid about both edges of IUSTB. Signal timing for this handshaking is shown in Figure
12.
If the subsystem does not declare itself busy, then it must respond to DTRQ going low by setting DTAK low within
approximately 1.5 us. Failure to do so will be classed by the RT as a subsystem failure and reported as such to the Bus
Controller.
It should be noted that IUSTB is also used for internal working in the RT. DTRQ being low should be used as an enable
for clocking data to the subsystem with IUSTB.
Once the receive data block has finished and been checked by the RT, GBR is pulsed low if the block is entirely correct
and valid. This is used by the subsystem as permission to make use of the data block If no GBR signal is generated,
then an error has been detected by the RT and the entire data block is invalid and no data words in it may be used.
If the RT is receiving data in an RT to RT transfer, the data handshaking signals will operate in an identical fashion but
there will be a delay of approx 70 µs between NBGT going low and DTRQ first going low. See Figure 10.
Figure 6 shows the operation of the data handshaking signals during transmit command with three, data words. As with
the receive command discussed previously, NBGT is pulsed low if the command is valid and for the RT. TX/RX will be
set high indicating a transmit data command. While the RT is transmitting its status word, it requests the first data word
from the subsystem by setting DTRQ low. The subsystem must then reply within approximately 13.5 µs by setting
DTAK low. By setting DTAK low, the subsystem is indicating that it has the data word ready to pass to the RT. Once
DTAK is set low by the subsystem, DTRQ should be used together with H/L and TX/RX to enable first the high byte and
then the low byte of the data word onto the internal highway IH08-IH715. The RT will latch the data bytes during IUSTB,
and will then return DTRQ high. Data for each byte must remain stable until IUSTB has returned low. Signal timing for
this handshaking is shown in Figure 11.
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Additional Data Information Signals
At the same time as data transfers take place, a number of information signals are made available to the subsystem.
These are INCMD, the subaddress lines SA0-4, the word count lines WC0-4 and current word count lines CWC0-4.
Use of these signals is optional.
INCMD will go active low while the RT is servicing a valid command for the RT. The subaddress, transmit/receive bit.
and word count from the command word are all ma a vailable to the subsystem as SA0-4, TX/RX and WC0-4
respectively. They may be sampled when INCMD goes low and will remain valid while INCMD is low.
The subaddress is intended to be used by the subsystem as an address pointer for the data block Subaddress 0 and
31 are mode commands, and there can be no receive or transmit data blocks associated with these. (Any data word
associated with a mode command uses different handshaking operations. If the subsystem does not use all the
subaddresses available, then some of the subaddress lines may be ignored.
The TX/RX signal indicates the direction of data transfer across the RT - subsystem interface. Its use is described in
the previous section.
The word count tells the subsystem the number of words to expect to receive or transmit in a message, up to 32 words.
A word count of all 0s indicates a count of 32 words.
The current word count is set to 0 at the beginning of a new message and is incremented following each data word
transfer across the RT - subsystem interface. (It is clocked on the falling edge of the second IUSTB pulse in each word
transfer). It should be noted that there is no need for the subsystem to compare the word count and current word count
to validate the number of words in a message. This is done by the RT.
Subsystem Use of Status Bits and Mode Commands
General Description
Use of the status bits and the mode commands is one of the most confusing aspects of MIL-STD-1553B. This is
because much of their use is optional, and also because some involve only the RT while others involve both the RT and
the subsystem.
The CT1999 allows full use to be made of all the status bits, and also implements all the mode commands. The
subsystem is given the opportunity to make use of status bits, and is only involved in mode commands which have a
direct impact on the subsystem.
The mode commands in which the subsystem may be involved are Synchronize, Sychronize with data word, Transmit
Vector Word, Reset and Dynamic Bus Control Allocation. The status bits to which the subsystem has access are
Service Request, Busy, Subsystem Flag and Dynamic Bus Control Acceptance. Operation of each of these mode
commands and of the status bits is described in the following sections.
The subsystem designer should note that all other mode commands and status bits are serviced internally by the RT,
and the subsystem has no access to them. In particular, the terminal flag and message error status bits and BIT word
contents are all controlled internally by the RT.
Synchronize Mode Commands
Once the RT has validated the command word and checked for the correct address, the SYNC line is set low. The
signal WC4 will be set low for a Synchronize mode command Figure 16, and high for a Synchronize with data word
mode command Figure 15. In a Synchronize with data word mode command, SYNC remains low during the time that
the data word is received. Once the data word has been validated, it is passed to the subsystem on the internal
highway IH08-IH715 in two bytes using IUSTB as a strobe signal and H/L as the byte indicator (high byte first followed
by low byte). SYNC being low should be used on the enable to allow IUSTB to clock synchronize mode data to the
subsystem.
If the subsystem does not need to implement either of these mode commands, the SYNC signal can be ignored, since
the RT requires no response from the subsystem.
Transmit Vector Word Mode Command
Figure 14 illustrates the relevant signal timings for an RT receiving a valid Transmit Vector Word mode command. The
RT requests data by setting VECTEN low. The subsystem should use H/L to enable first the high byte and then the low
byte of the Vector word onto the internal highway IH08-IH715.
It should be noted that the RT expects the Vector word contents to be already prepared in a latch ready for enabling
onto the internal highway when VECTEN goes low. If the subsystem has not been designed to handle the Vector word
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mode command, it will be the fault of the Bus Controller if the RT receives such a command. Since the subsystem is
not required to acknowledge the mode command, the RT will not be affected in any way by Vector word circuitry not
being implemented in the subsystem. It will however transmit a data word as the Vector word, but this word will have
no meaning.
Reset Mode Command
Figure 8 shows the relevant signal timings for an RT receiving a valid reset mode command. Once the command
word has been fully validated and serviced, the RESET signal is pulsed low. This signal may be used as a reset
function for subsystem interface circuitry.
Dynamic Bus Allocation
This mode command is intended for use with a terminal which has the capability of configuring itself into a bus
controller on command from the bus. The line DBCREQ cannot go true unless the DBCACC line was true at the time
of the valid command, i.e. tied low. For terminals acting only as RTs, the signal DBCACC should be tied high
(inactive), and the signal DBCREQ should be ignored and left unconnected.
Use of the Busy Status Bit
The Busy Bit is used by the subsystem to indicate that it is not ready to handle data transfers either to or from the RT.
The RT sets the bit to logic one if the BUSY line from the subsystem is active low at the time of the second falling
edge of INCLK after INCMD goes low. This is shown in Figure 13. Once the Busy bit is set, the RT will stop all receive
and transmit data word transfers to and from the subsystem. The data transfers in the Synchronize with data word
and Transmit Vector word mode commands are not affected by the Busy bit and will take place even if it has been set.
It should be noted that a minimum of 0.5 µs subaddress decoding time is given to the subsystem before sending of
status bits. This allows the subsystem to selectively set the Busy bit if for instance one subaddress is busy but others
are ready. This option will prove useful when an RT is interfacing with multiple subsystems.
Use of the Service Request Status Bit
The Service Request bit is used by the subsystem to indicate to the Bus Controller that an asynchronous service is
requested.
The timing of the setting of this bit is the same as the Busy bit and is shown in Figure 13. Use of SERVREQ has no
effect on the RT apart from sening the Service Request bit.
It should be noted that certain mode commands require that the last status word be transmitted by the RT instead of
the current one, and therefore a currently set status bit will not be seen by the Bus Controller. Therefore the user is
advised to hold SERVREQ low until the requested service takes place.
Use of the Subsystem Status Bit
This status bit is used by the RT to indicate a subsystem fault condition. If the subsystem sets SSERR low at any
time, the subsystem fault condition in the RT will be set, and the Subsystem Flag status bit will subsequently be set
The fault condition will also be set if a handshaking failure takes place during a data transfer to or from the
subsystem. The fault condition is cleared on power-up or by a Reset mode command.
Dynamic Bus Control Acceptance Status Bit
DBCACC, when set true, enables an RT to configure itself into a Bus Controller, if the subsystem has the capability,
by allowing DBCREQ to pulse true and BIT TIME 18 to be set in the status response. If Dynamic Bus Control is not
required then DBCACC must be tied high. DBCACC tied high inhibits DBCREQ and clears BIT TIME 18 in the status
response.
Bus Driver/Receiver Interface
Receive Data
The decoder chip requires two TTL signals (PDIN & NDIN) to represent the data coming in from the bus. PDIN should
be driven to a logic level ‘1’ when the bus waveform exceeds a specified positive threshold and NDIN should be
driven to a logic level ‘1’ when a specified negative threshold is exceeded. During the quiet period on the bus both
signals should be at the same logic level. All the bus receivers must be permanently enabled, the selection if the bus
in use is done within the ASIC.
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Transmit Data
The signals generated by the encoder chip (PDOUT & NDOUT) are of the same format as the receive data The only
difference is that the TTL signals are negative logic, e.g. the signal is active when on logic level "0". This means that
when the encoder is quiet both PDOUT & NDOUT are at logic level ‘1’. Both the signals should be used in conjunction
with TXEN and the appropriate driver enable, e.g. (CS0 - enable for bus 0). TXEN only enables the driver when it
should be transmitting, and the driver enable routes the data on to the bus in use.
Figure 5 shows an example of a typical interface circuit between the CT1999 and a driver/receiver unit.
BUS CONTROL OPERATION
To enable its use in a bus controller each chip in the chipset has additional logic within it. This logic can be enabled by
pulling the pin labelled RT/BC low. Once the chipset is in bus control mode, all data transfers must be initiated by the
bus control processor correctly commanding the chipset via the subsystem interface. In bus control mode six inputs are
activated which in RT mode are inoperative and four signals with dual functions exercise the second function (the first
being for the RT operation).
To use the CT1999 as a 1553B bus control interface, the bus control processor must be able to carry out four basic
bus-related functions. Two inputs, BCOPA and BCOPB allow these four options to be selected. The option is then
initiated by sending a negative-going strobe on the BCOPSTB input. BCOPSTB must only be strobed low when NDRQ
is high. This is particularly important when two options are required during a single transfer.
With these options all message types and lengths can be handled. Normal BC/RT exchanges are carried out in the
chipset option zero. This is selected by setting BCOPA and BCOPB to a zero and strobing BCOPSTB. On receipt of the
strobe, the CT1999 loads the command word from an external latch using CWEN and H/L The command word is
transmitted down the bus. The TX/RX bit is, however, considered by the chipset as being its inverse and so if a transmit
command is sent to a RT, Figure 17, the chipset in BC mode believes it has been given a receive command. As the RT
returns the requested number of data words plus its status, the BC chipset carries out a full validation check and
passes the data into the subsystem using DTRQ, DTAK, H/L, IUSTB and CWC as in RT operation. It also supplies
GBR at the end of a valid transmission. Conversely, a receive command sent down the bus is interpreted by the BC
chipset as a transmit command, and so the requisite data words are added to the command word, see Figure 18.
For mode commands, where a single command word is required, option one is selected by strobing BCOPSTB when
BCOPA is high and BCOPB is low. On receiving the strobe, the command word is loaded from the external latch using
CWEN and H/L, the correct sync and parity bits are added and the word transmitted, see Figure 20. Mode commands
followed by a data word requires option two. Option two, selected by strobing BCOPSTB while BCOPA is low and
BCOPB is high, loads a data word via DWEN and H/L, adds sync and parity and transmits them to the bus, see Figure
21. If the mode code transmitted required the RT to return a data word, then selecting option three by strobing
BCOPSTB when BCOPA and BCOPB are both high will identify that data word and if validated, output it to the
subsystem interface using RMDSTB and H/L This allows data words resulting from mode codes to be identified
differently from ordinary data words and routed accordingly, see Figure 22. All received status words are output to the
subsystem interface using STATSTB and H/L.
In BC option three, if the signal PASMON is active, then all data appearing on the selected bus is output to the
subsystem using STATSTB for command and status words or RMDSTB for data words.
RT to RT transfers require the transmission of two command words. A receive command to one RT is contiguously
followed by a transmit command to the the other RT. This can be achieved by selecting option one followed by option
zero for the second command. The strobe (BCOPSTB) for option zero must be delayed until NDRQ has gone low and
returned high following the strobe for option one. The RT transmissions are checked and transferred in the subsystem
interface to the bus control processor, see Figure 19.
Note: For all BC operations, BCOPA and BCOPB must remain valid and stable for a minimum of 1 µs following the
leading (negative going) edge of BCOPSTB.
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Pin Description
Signal
Hybrid
Sink or Source
Signal Description
RX DATA 0/1
SINK
Positive Date In. This should be a TTL description of the positive, half of the
Manchester code data on the bus. It should be driven to a logic level “1” when
a predetermined positive threshold is exceeded on the bus.
RX DATA 0/1
SINK
Negative Data In. This should be a TTL description of the negative half of the
Manchester code data on the bus. It should be driven to a logic level “1” when
a predetermined negative threshold is exceeded on the bus.
TX INHIBIT 0/1
SOURCE
Transmitter Enable. Goes low when the transmitter is transmitting. Should be
used to enable the bus drivers.
TX DATA
SOURCE
Positive Data Out - When this signal goes high the bus should be driven
positive.
TX DATA
SOURCE
Negative Data Out - When this signal goes high the bus should be driven
negative.
RTAD 0-4
SINK
RT address lines - These should be hardwired by the user. RTAD4 is the most
significant bit.
RTADPAR
SINK
RT address parity line - This must be hardwired by the user to give odd parity.
BCSTEN 0/1
SINK
Recognition of Broadcast command enable - When low the recognition of
broadcast command is prevented on the specified bus.
6MCK
SINK
6 Megahertz master clock.
IH 08
IH 19
IH 210
IH 311
IH 412
IH 513
IH614
IH715
SINK/SOURCE
DTRQ
SOURCE
Data Transfer Request - Goes low to request a data transfer between the
ASIC and subsystem. Goes high at the end of the transfer.
DTAK
SINK
Data Transfer Acknowledge - Goes low to indicate that the subsystem is
ready for the data transfer.
IUSTB
SOURCE
Interface Unit Strobe - This is a double pulse strobe used to transfer the two
bytes of data
H/L
SOURCE
High/Low - Indicates which byte of data is on the internal highway. Logic level
"0" for least significant byte.
GBR
SOURCE
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.
NBGT
SOURCE
New Bus Grant - Pulses low whenever a new command is accepted by the
ASIC.
TX/RX
SOURCE
Transmit/Receive - The state of this line informs the subsystem whether it is
to transmit or receive data The signal is valid while INCMD is low.
INCMD
SOURCE
In Command - Goes low when the RT is servicing a valid command. The
subaddress and word count lines are valid while the signal is low.
WC 0-4
SOURCE
Word Count - These five lines specify the requested number of data words to
be received or transmitted. Valid when INCMD is low.
Aeroflex Circuit Technology
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.
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Pin Description (Cont.)
Signal
Hybrid
Sink or Source
Signal Description
SA 0-4
SOURCE
Sub Address - These five lines are a label for the data being transferred. Valid
when INCMD is low.
CWC 0-4
SOURCE
Current Word Count - These five lines define which data word in the message
is currently being transferred.
SYNC
SOURCE
Synchronize - Goes low when a synchronize mode code is being serviced.
VECTEN/DWEN
SOURCE
Vector Word Enable/DataWord Enable - In the RT mode, this signal is
provided to enable the contents of the vector word latch (which is situated in
the subsystem) onto the ASIC’s internal highway. This signal, when in the Bus
Controller mode, is used to enable mode code data from the subsystem onto
the internal highway.
RESET
SOURCE
Reset - This line pulses low for 500ns on completion of the servicing of a valid
and legal mode command to reset remote terminal.
SSERR
SINK
Subsystem Error - By taking this line low, the subsystem can set the
Subsystem Flag in the Status Word.
BUSY
SINK
Busy - This signal should be driven low if the subsystem is not ready to
perform a data transfer to or from the ASIC.
SERVREQ
SINK
Service Request - This signal should be driven low to request an
asynchronous transfer and left low until the transfer has taken place.
INCLK
SOURCE
Internal Clock (2 MHz) - This is made available for synchronization use by the
subsystem if required. However, many of the outputs to the subsystem are
asynchronous.
EOT
SOURCE
End of Transmission - Goes low if a valid sync plus two data bits do not
appear in time to be contiguous with preceding word.
RTADER
SOURCE
Remote Terminal Address Error - This line goes low if an error is detected in
the RT address parity of the selected receiver. Any receiver detecting an error
in the RT address will turn itself off.
HSFAIL
SOURCE
Handshake Failure - This line pulses low if the allowable time for DTAK
response has been exceeded during the ASIC/subsystem data transfer
handshaking.
LSTCMD/CWEN
SOURCE
Last Command/Command Word Enable - This line pulses low when
servicing a valid and legal mode command to transmit last command. When in
RT mode this line must not be used to enable data from the subsystem. This
line also pulses low, when in the Bus Control mode, when a command word is
required for transmission.
STATEN/
STATSTB
SOURCE
Status Enable/Status Strobe - This line pulses low to enable the status word
onto the internal highway for transmission. When in RT mode this line must not
be used to enable data from the subsystem. This line also pulses high, when in
the Bus Control mode, to strobe received status words into the subsystem.
When PASMON is true this line pulses high for Command and Status words.
BITEN/
RMDSTB
SOURCE
Built In Test Enable/Receive Mode Data Strobe - This line pulses low when
servicing a valid and legal mode command to transmit the internal BIT word.
This signal is for information only and must not be used to enable data from the
subsystem. This line also pulses high when in the Bus Control mode when
mode data is received to be passed to the subsystem and when data is passed
to the subsystem during PASMON.
DWSYNC
SOURCE
Data Word Sync - This line goes low if a data word sync and two Manchester
biphase bits are valid.
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Pin Description (Cont.)
Signal
Hybrid
Sink or Source
Signal Description
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.
DBCREQ
SOURCE
Dynamic Bus Control Request - This line will pulse low when the status reply
for a mode code Dynamic Bus Control has finished where the accept bit was
set.
VALD
SOURCE
Valid Data - This line will pulse low when a valid data word is received.
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Pin Description (Cont.)
Signal
Hybrid
Sink or Source
Signal Description
BUF INH
SINK
Buffer Inhibit - A low on this line causes the Buffered Signals to assume a
high impedance state.
IH ENA
SINK
Internal Highway Enable - A low on this line enables the Internal Highway
transceiver to transmit or receive data which is controlled by the IH DIR Line.
IH DIR
SINK
Internal Highway Direction - Controls the direction of data through the
Internal Highway Transceiver.
High = To Subsystem
Low = From Subsystem
RX DATA 0/1
SINK
Positive Date In. This should be a TTL description of the positive, half of the
Manchester code data on the bus. It should be driven to a logic level “1” when
a predetermined positive threshold is exceeded on the bus.
RX DATA 0/1
SINK
Negative Data In. This should be a TTL description of the negative half of the
Manchester code data on the bus. It should be driven to a logic level “1” when
a predetermined negative threshold is exceeded on the bus.
TX INHIBIT 0/1
SOURCE
Transmitter Enable. Goes low when the transmitter is transmitting. Should be
used to enable the bus drivers.
TX DATA
SOURCE
Positive Data Out - When this signal goes high the bus should be driven
positive.
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
NEXT
....
Data
Word
..
Status
Word
§
Command
Word
Status
Word
Data
Word
Data
Word
....
Data
Word
§
Command
Word
..
Status
Word
Data
Word
Data
Word
....
Data
Word
..
§
Command
Word
Controller to
RT Transfer
Receive
Command
Data
Word
Data
Word
RT to
Controller
Transfer
Transmit
Command
..
RT to RT
Transfer
Receive Transmit
Command Command
NEXT
NEXT
Mode Command
Without Data
Word
Status
Word
§
Command
Word
NEXT
Mode
Command
..
Status
Word
Mode Command
With Data
Word
(Transmit)
Mode
Command
..
Status
Word
Data
Word
§
Command
Word
Mode Command
With Data
Word
(Receive)
Mode
Command
Data
Word
..
Status
Word
§
Command
Word
NEXT
NEXT
NOTE:
§ = Intermessage Gap
. . = Response Time
Figure 1 – Typical Message Formats
T/R
Bit
Mode Code
Function
Associated
Data Word
1
00000
Dynamic Bus Control
No
No
1
00001
Synchronize
No
Yes
1
00010
Transmit Status Word
No
No
1
00011
Initiate Self Test
No
Yes
1
00100
Transmitter Shutdown
No
Yes
1
00101
Override Transmitter Shutdown
No
Yes
1
00110
Inhibit Terminal Flag Bit
No
Yes
1
00111
Override lnhibit Terminal Flag Bit
No
Yes
1
01000
Reset Remote Terminal
No
Yes
1
01001
Reserved
No
TBD
↓
↓
↓
Broadcast Command
Allowed
↓
1
01111
Reserved
No
TBD
1
10000
Transmit Vector Word
Yes
No
0
10001
Synchronize
Yes
Yes
1
10010
Transmit Last Command
Yes
No
1
10011
TransmitBlTWord
Yes
No
0
10100
Selected Transmitter Shutdown
Yes
Yes
0
10101
Override Selected Transmitter
Shutdown
Yes
Yes
1 or 0
10110
Reserved
Yes
TBD
↓
1 or 0
11111
↓
↓
Reserved
↓
Yes
TBD
Figure 2 – Assigned Mode Codes
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Aeroflex Circuit Technology
SYNC
12
11
10
9
8
7
6
5
4
3
2
1
0
Bus 0 Shutdown
Broadcast Transmit Data Received
Word Count High
Word Count Low
REMOTE TERMINAL
ADDRESS
12
1
1
1
1
1
1
1
1
1
Parity
RESERVED
Transmitter Timeout Flag
3
Terminal Flag
14
Subsystem Handshake Failure
13
Dynamic Bus Control Acceptance
DATA WORD
12
Loop Test Failure
11
Subsystem Flag
10
Mode T/R Bit Wrong
9
Busy
8
Illegal Mode Command
7
Broadcast Command Received
COMMAND
WORD
6
Service Request
5
13
Bus 1 Shutdown
5
Instrumentation
STATUS WORD
14
Bus 2 Shutdown
4
Message Error
SYNC
15
Bus 3 Shutdown
BIT WORD
Transmitter Timeout on Bus 0
SYNC
3
Transmitter Timeout on Bus 1
2
Transmitter Timeout on Bus 2
1
Transmitter Timeout on Bus 3
BIT TIMES
15
16
17
18
1
19
20
5
1
5
5
1
REMOTE TERMINAL
ADDRESS
T/R
SUBADDRESS/MODE
DATA WORD
COUNT/MODE CODE
P
16
1
DATA
P
LSB
20
P
Note: T/R – Transmit/Receive
P – Parity
Figure 3 – Word Count
SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
One Bit Time
1MHz
Clock
(+) -
NRZ
Data
(+) -
(0) -
(0) -
(+) -
=
Manchester
(0) -
Bi-Phase
(-) -
Figure 4 – Data Encoding
CT1999
+
TX DATA OUT
RX DATA IN
RX DATA OUT
ACT4453
RX DATA OUT
1553B
BUS "A"
Driver/
Receiver 0
PDIN "0"
NDIN "0"
TX DATA IN
TX DATA IN
TX DATA
XFR0
TX DATA
TX DATA OUT
RX DATA IN
TX INHIBIT "0"
+
TX DATA OUT
RX DATA IN
RX DATA OUT
ACT4453
RX DATA OUT
1553B
BUS "B"
Driver/
Receiver 1
PDIN "1"
NDIN "1"
TX DATA IN
TX DATA IN
TX INHIBIT "0"
XFR1
TX DATA OUT
RX DATA IN
TX INHIBIT "1"
TX INHIBIT "1"
Figure 5 – Example of an Interface between the CT1999 and Driver/Receiver
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
PDIN
NBGT
INCMD
DTRQ
IUSTB
H/L
GBR
EOT
Figure 6 – Transfer of three Data Words from RT 03 to BC
PDIN
NBGT
INCMD
DTRQ
IUSTB
H/L
GBR
EOT
Figure 7 – Transfer of two Data Words from BC to RT 03
PDIN
NBGT
INCMD
DTRQ
IUSTB
H/L
GBR
EOT
Figure 8 – Mode Command Reset Remote Terminal
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
PDIN
NBGT
INCMD
DTRQ
IUSTB
H/L
GBR
EOT
Figure 9 – RT to RT transfer of four data words
(This RT sending the data)
PDIN
NBGT
INCMD
DTRQ
IUSTB
H/L
GBR
EOT
Figure 10 – RT to RT transfer of four data words
(This RT receiving the data)
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
DTRQ
Subsystem Reply Time < 13.5µs
Don’t Care
DTAK
250 nsec
250 nsec
IUSTB
500 nsec
H/L
CWC0-4
Valid
Incremented
Enable High Byte of TX
Data on Internal
Highway
Enable Low Byte of
TX Data on Internal
Highway
Figure 11 – Handshaking for Tx Data Transfers
DTRQ
Subsystem Reply Time < 1.5µs
Don’t Care
DTAK
250 nsec
250 nsec
IUSTB
500 nsec
H/L
Internal
Highway
CWC0-4
High Byte Valid
Low Byte Valid
Valid
Incremented
Figure 12 – Handshaking for Rx Data Transfers
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
NBGT
1.0µs Minimum
TX/RX
Previous command value
Valid
SA4-SA0
Previous command value
Valid
WC4-WC0
Previous command value
Valid
CWC4-CWC0
INCMD
INCLK
BUSY Latch here
Figure 13 – New Command Initialization
NBGT
INCMD
VECTEN
1.5µs
approx.
H/L
}
}
Enable high byte of
vector word onto
internal highway
Enable low byte of
vector word onto
internal highway
Figure 14 – Transmit Vector Word Command
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
1
0 0
1
NBGT
0
1
INCMD
0
1
SYNC
0
1
ILUSTB
0
1
EOT
0
1
WC4
0
1
H/L
0
PDIN
Figure 15 – Synchronize (with data) mode command
1
0 0
1
NBGT
0
1
INCMD
0
1
SYNC
0
1
IUSTB
0
1
EOT
0
1
WC0
0
PDIN
Figure 16 – Synchronize (no data) mode command
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Aeroflex Circuit Technology
19
SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
NBGT
GBR
INCMD
RTO
VALD
STATSTB
VALC
EOT
C/D
IUSTB
H/L
DTRG
NDRG
CWEN
PDIN
BCOPSTB
Figure 17 – BUS Controller sending command to RT 10001 to transmit two data words
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
NBGT
GBR
INCMD
RTO
VALD
STATSTB
VALC
EOT
C/D
IUSTB
H/L
DTRG
NDRG
CWEN
PDIN
BCOPSTB
Figure 18 – BUS Controller sending command to RT 10001 to receive two data words
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
IH412
IH311
IH210
IH19
IH06
H/L
IUSTB
C/D
TxSTB
NBGT
INCMD
VALC
VALD
STATSTB
DTRG
CWC0
CWC1
TREQ
GBR
EOT
TXEN
PDOUT
RTO
IH715
IH614
IH613
BCOPSTB
BCOPA
BCOPB
NDRG
PDIN
CWEN
Figure 19 – BUS Controller commanding RT 10001 to transmit two data words at RT 00001
BCOPSTB
BCOPA
BCOPB
PDIN
TXSTB
CWEN
H/L
STATSTB
Figure 20 – BUS Controller sending mode command transmit
status word mode code 00010
BCOPSTB
BCOPA
BCOPB
PDIN
NDRQ
CWEN
DWEN
H/L
Figure 21 – BUS Controller sending mode command
synchronize mode code 10001
BCOPSTB
BCOPA
BCOPB
PDIN
DWEN
H/L
STATSTB
RMDSTB
Figure 22 – BUS Controller sending mode command transmit
vector mode code 10000
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Pin Out Description
Pin #
Pin #
FP
Function
Pin #
Pin
# FP
Function
Pin #
Pin
# FP
Function
1
1
NC
31
31
REQBUSB
61
59
ERROR
2
2
CWC 00 (LSB)
32
32
REQBUSA
62
60
LTFAIL
3
3
SA 04 (MSB)
33
33
COMMON & CASE
63
61
MANER
4
4
SA 03
34
34
IH DIR
64
62
PARER
5
5
SA 02
35
35
NC
65
63
VALD
6
6
CWC 04 (MSB)
36
36
IH ENA
66
64
RTADER
7
7
CWC 03
37
37
IH 00/08 (LSB)
67
65
RX DATA 01
8
8
CWC 02
38
38
IH 01/09
68
66
RX DATA 01
9
9
CWC 01
39
39
IH 02/10
69
67
+5 VIN
10
10
GBR
40
40
IH 03/11
70
68
TX INHIBIT 01
11
11
H/L
41
41
IH 04/12
71
69
TX INHIBIT 00
12
12
STATEN/STATSTB
42
42
IH 05/13
72
70
TX DATA
13
13
EOT
43
43
IH 06/14
73
71
TX DATA
14
14
SA 01
44
44
IH 07/15 (MSB)
74
72
SERVREQ
15
15
SA 00 (LSB)
45
NC
75
73
TXTO
16
16
INCMD
46
NC
76
74
DBCACC
17
17
TX/RX
47
45
RTADPAR
77
75
RESET
18
18
DTRQ
48
46
RTAD 00 (LSB)
78
76
RT/BC
19
19
VECTEN/DWEN
49
47
RTAD 01
79
77
DBCREQ
20
20
NBGT
50
48
RTAD 02
80
78
HSFAIL
21
21
SYNC
51
49
RTAD 03
81
79
LSTCMD/CWEN
22
22
INCLK
52
50
RTAD 04 (MSB)
82
80
BITEN/RMDSTB
23
23
IUSTB
53
51
CMSYNC
83
81
BUSY
24
24
BUF INH
54
52
DWSYNC
84
82
WC 04 (MSB)
25
25
DTAK
55
53
BCSTEN 00
85
83
WC 03
26
26
BCOPA
56
54
RX DATA 0
86
84
WC 00 (LSB)
27
27
BCOPSTB
57
55
RX DATA 0
87
85
SSERR
28
28
BCOPB
58
56
BCSTEN 01
88
86
WC 02
29
29
PASMON
59
57
RTO
89
87
WC 01
30
30
NDRQ
60
58
6 MCK
90
88
NC
Aeroflex Circuit Technology
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SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
Plug In Package Outline
.225
MAX
2.400
MAX
1.600
MAX
Lead 1 & ESD
Designator
.200
MIN
2.200
.090
.135
Pin 1
Pin 3
.050
TYP
Pin 43
Pin 45
Pin 44
Pin 2
.018 DIA
TYP
1.300 1.100
Pin 89
Pin 47
Pin 90
Pin 88
.135
.100
TYP
Pin 48
Pin 46
2.100
Flat Package Outline
2.400
MAX
.010
±.002
.015
Pin 45
Pin 88
.225
MAX
1.600
MAX
Lead 1 & ESD
Designator
.300
Min
Pin 44
.115
TYP
Aeroflex Circuit Technology
2.150
.050 Lead Centers
44 Leads/Side
24
Date
Code
.080 REF
SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700
CIRCUIT TECHNOLOGY
Ordering Information
Model Number
CT1999
CT1999-FP
Screening
Package
Military Temperature, -55°C to +125°C,
Screened to the individual test methods of MIL-STD-883
Plug in
Aeroflex Circuit Technology
35 South Service Road
Plainview New York 11803
Flat Package
Telephone: (516) 694-6700
FAX:
(516) 694-6715
Toll Free Inquiries: 1-(800)THE-1553
Specifications subject to change without notice.
Aeroflex Circuit Technology
25
SCDCT1999 REV B 8/14/01 Plainview NY (516) 694-6700