CT2553-FP AEROFLEX [Aeroflex Circuit Technology], CT2553-FP Datasheet - Page 10

• Manufacturer Part Number: CT2553-FP
• Description: CT2553 / 2554 / 2555 / 2556 Advanced Integrated MUX (AIM) Hybrid FOR MIL-STD-1553
• Manufacturer: AEROFLEX [Aeroflex Circuit Technology]

Aeroflex Circuit Technology
CPU TO REGISTER OPERATIONS. The CPU
selects a register by asserting MEM/REG low and
A2 to a logic 0 (for internal registers) or logic 1 (for
external registers) with A0 and A1 indicating the
appropriate register address (See Figures 28-32).
The signals EXTEN and EXTLD are used to
access the external registers.
CONFIGURATION REGISTER. The Configuration
Register is a 16-bit read/write register used to
define the 1553 operating mode (BC, RTU, or MT);
define selectable 1553 Status Word bits (RTU
only); select stop-on-error option; and support the
double buffering scheme (See Figure 11).
INTERRUPT MASK REGISTER (BC/RTU). This
register is a 16-bit read/write register used to
enable/mask interrupt conditions. If an interrupt
condition occurs and the corresponding Interrupt
Register bit has been enabled (set to logic 1) pin
72, INT will be pulsed low during the respective
End of Message (EOM) cycle (See Figure 12). Not
Used bit locations can optionally be used for
storing user flags.
EOM
FORMAT
ERROR/
STATUS SET
BC EOM
INTERRUPT
Figure 12 – Interrupt Mask Register
15
1 1 1 1 1 1 1
BC EOM
FORMAT ERROR/STATUS SET
NOT USED
EOM
End of message. Set by CT2553 in BC or
RTU mode following each 1553 transfer
(regardless of validity).
Set if one of the following occurs: .
Loop Test Failure: Received word does
not match last word transmitted.
Message Error: Received message
contained a violation of any of the 1553
message validation criteria (parity, sync,
manchester encoding, bit/word count, etc.)
Time-Out: Expected transmission was
not received during the allotted time.
Status Set: Received Status Word
contained status bit(s) set or address error.
Bus Controller End of Message. Set by the
CT2553 following transmission of all
messages within the current Message Block
(Current area message count = FFFF).
9 8 7
DEFINITION
USED
NOT
4 3 2 1 0
10
RTU/BC
MT
CURRENT AREA B/A
STOP ON ERROR
SUBYSTEM FLAG
SERVICE REQUEST
BUSY
DB ACCEPT
STOP ON ERROR
CURRENT AREA B/A Selects Current Area Pointers.
RTU/BC
START/RESET
register is used to reset the CT2553 and to start
the BC and MT operations, as illustrated in
Figure 13.
Note: A logic 0 causes the corresponding bit within the RTU’s status
word to be set to a logic 1.
CONTROLLER
START
RESET
BIT NAME
BIT NAME
15
Figure 11 – Configuration Register
Figure 13 – Start/Reset Register
15
CONTROLLER START
START
RESET
RESET
Issued by the CPU to start
message block transmission (BC
Operation) or to begin reception of
1553 messages (MT Operation).
Issued by the CPU to place the
CT2553 in the power-on condition;
(1) aborts 1553 transfers currently
in progress, and (2) resets
Configuration and Interrupt Mask
Register bits (logic 0).
REGISTER.
SCDCT2553 REV B 8/6/99 Plainview NY [phone]
NOT USED
Sets/resets 1553 Status Word flag.
Sets/resets 1553 Status Word flag.
Sets/resets 1553 Status Word flag.
Sets/resets 1553 Status Word flag.
BC will halt message transfer after
completing current EOM cycle.
RTU or BC-MT Operation Select.
9 8 7
BIT 1
BIT15
1
0
0
0
1
1
DEFINITION
8 7
BIT 14
BIT 0
DEFINITION
1 1 1 1 1 1 1 1
0
1
0
1
0
1
This
SUBSYSTEM FLAG
SERVICE REQUEST
BUSY
DB ACCEPT
4 3 2 1 0
Operation
Illegal
RTU
write-only
BC
MT
0