CT2553-PCB Aeroflex Circuit Technology, CT2553-PCB Datasheet - Page 8

• Manufacturer Part Number: CT2553-PCB
• Description: Advanced Integrated Mux Aim Hybrid For Mil-std-1553 / Sae-as15531 In Pcb Style
• Manufacturer: Aeroflex Circuit Technology

EOM
SOM
CHB/CHA
(RTU ONLY)
ERROR FLAG
The contents of the fourth word of the stack entry depends
upon the 1553 operating mode selected. In BC mode, It
contains the address of the associated 1553 message (Data
Block). In RTU mode, it contains the complete (received)
1553 Command Word.
Note: In BC operation, the CT2553-PCB always writes the BSW to RAM
with Bit-13. CHB/CHA toggles as per the message control word setting.
EOM
SOM
CHB/CHA
ERROR
FLAG
STATUS
SET
FORMAT
ERROR
RESPONSE
TIMEOUT
FIGURE 8 – DESCRIPTOR STACK - BLOCK
SCDCT2553PCB Rev A Preliminary 7/13/06
BIT NAME
LOOP
TEST FAIL
15
transfer regardless of whether any errors
were detected.
and Reset upon completion of the
transfer.
Set in RTU mode to indicate whether the
message was received on 1553 bus A or
bus B. Toggles to indicate channel, in BC
mode.
Indicates that an error was detected within
the message transfer. The specific error
condition(s) are identified in bits 8-11.
Set in BC mode to indicate that a status
flag bit was set within the received RTU
Status Word or that the RTU address did
not match the associated Command. Set
in BC mode when the message error bit is
set within the received RTU Status Word.
Also set in RTU mode (RT-RT transfer;
CT2553-PCB is acting as the receiving
RT) when the transmitting RTU Status
Word contains an incorrect address. Also,
set in BC or RTU mode if the message
violates MIL-STD-1553 (parity,
Manchester, sync bit count,
non-contiguous data or word count
errors).
Set in BC mode if the addressed RTU did
not respond within 14µs. Also set when
acting as a receiving RT (RT-RT transfer)
if the transmitting RT does not respond in
the specified 1553 response time.
Set when the CT2553-PCB does not pass
the Loop Test. See Self Test paragraph.
Set at the completion of a message
Set at the beginning of a message transfer
STATUS WORD
8 7
LOOP TEST FAIL
RESPONSE TIME OUT (BC ONLY)
FORMAT ERROR
STATUS SET (BC ONLY)
1 1 1 1 1 1 1 1
DEFINITION
0
8
STACK POINTER.
maintained at a specified location in shared RAM for each
Descriptor Stack (SP-A: 0100H; SP-B: 0104H). Each
Stack Pointer must be initialized by the CPU to point to
the Descriptor Stack Entry to be used for the first
MIL-STD-1553 transmission. The current area SP is
automatically incremented by four following each
message transfer thereby always pointing to the next
Block Status Word.
LOOK-UP TABLE (RTU).
Look-Up Table is used to indicate the data blocks to be
used for individual commands. Look-Up is based upon the
T/
1553 Command Word. See RTU Operation for detailed
operation; two tables are provided for double buffering in
the RTU mode.
MULTIPLE BUFFERING (BC/RTU).
areas of shared RAM can be used to store additional
stacks, tables, data blocks and/or user (non 1553-related)
data. In this way, multiple data blocks (RTU) or messages
(BC) can be stored for later use: simply update respective
pointers and initiate the appropriate start conditions. (BC
mode requires SP, message block address and message
count updating while in RTU mode, the SP and Look-Up
Table entry must be updated).
CT2553-PCB REGISTERS
The CT2553-PCB is controlled through the use of three
internal registers: Interrupt Mask Register, Configuration
Register and a Start/Reset Register. In addition, the
CT2553-PCB can access up to four external, user supplied
registers (See Table 2). Possible external register
applications include: CPU Time Tag storage and RTU
Address assignment (See Figures 9 and 10).
Note: The Stack Pointer is maintained internally using an 8-BIT
REGISTER for the HIGH BYTE and an 8-BIT COUNTER for the
LOW BYTE. The high byte remains constant (user value) while
the low byte will wrap around from FF(H) to 00(H). For example:
a current Stack Pointer value of 00 FF(H) will increment to 00
00(H) and not 01 00 (H).
R
(transmit/receive) and Subaddress bits of the received
A STACK POINTER (SP) is
A data block address
Aeroflex Plainview
Unused