• Registers are always 32 bit / 4 byte• memory is accessed directly• when memory cannot be accessed kind of flag is on

Command ID Block Nr. Nr. of Words

Command Word 1

Command Word 2

…

Marker Checksum

Command ID Block Nr. Nr. of Words

Command Word 1

...

End Marker Word

SW 0 8 16 24 31HW 31 24 16 8 0

Protocol for RCU-specific Commands

Command ID Block Nr. Nr. of Words

Status Word

Result Word 1

…

Marker Checksum

Command ID Block Nr. Nr. of Words

Status Word

Result Word ...

End Marker Word

SW 0 8 16 24 31HW 31 24 16 8 0

Protocol for RCU-specific Results

Command ID: (8 bit)

Command identifier (for details, see 7.2.1)

Command identifier

Command identifier

Command identifier

Safety message identifier (1 if the message is a safety message, 0 if not)

Packed format bit (1 if the message contains packed 3 * 10 bit words.

Used for Pedestal Data)

Not used/Don’t care. Available for future use

Not used/Don’t care. Available for future use

Identifier Meaning

0001 Single read

0010 Single write

0011 Multiple read

0100 Multiple write

0101 Random read

0110 Random write

Block Nr: (8 bit)

The block number reflects if there are more instructions to handle.It is decremented inbetween one collection of instructions / blocks

Number of Words: (16 bit)

Number (Integer) of 32 bit data words in command block.Including information word and marker word.

Marker: (16 bit)

Marker word id, coded as AA55 (hex).

Checksum: (16 bit)

Checksum, which will be compared with the checksum computedby the Configuration Module/DCS IM

End Marker Word: (32 bit)

End marker id, coded as DD33 (hex).

Identifier Meaning0001 Single read:

- address word

0010 Single write:- address word- Data

0011 Multiple read- address word- number of data words to read

0100 Multiple write- address word- number of data words- data word 1 :- data word N

0101 Random read- address word 1- address word 2 :- address word N

0110 Random write

- address word 1- data word 1- address word 2- data word 2 :- address word N- data word N

Possible Commands:(TPC-RCU)

FEE Server(DIM - Server on RCU - Card)

PVSS Server(DIM - Server)

FEE Client(DIM - Client)

InterCom Layer(Application layer)

DatabaseAccess

PVSS Client (DIM - Client)

Communication Layers