SpW-10X

Ref.:

UoD_SpW-10X_

 

 

 

 

SpaceWire Router

 

UserManual

 

 

 

 

Issue:

3.4

 

 

 

 

 

User Manual

 

 

 

 

 

Date:

11th July 2008

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

incrementing read

 

 

 

 

 

 

 

 

 

4. The data length is

 

 

 

 

 

 

 

 

 

not 4 in a verified

 

 

 

 

 

 

 

 

 

write command.

 

 

 

 

 

 

 

 

 

5. The data length is

 

 

 

 

 

 

 

 

 

not 8 in a read

 

 

 

 

 

 

 

 

 

modify write

 

 

 

 

 

 

 

 

 

command.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Invalid Register

The address field is

 

Yes

RMAP Command not

 

10

 

Address

addressing an unknown

 

 

implemented or not

 

 

 

 

 

register for a read command

 

 

authorised

 

 

 

 

 

 

or a read only register in a

 

 

 

 

 

 

 

 

 

write command.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Read Modify

The read modify write data

 

Yes

RMW Data Length Error

11

 

Write Data

length is not 8

 

 

 

 

 

 

 

Length Error

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Invalid

The destination logical

 

Yes

Invalid Destination

 

12

 

Destination

address is invalid. The

 

 

Logical Address

 

 

 

Logical Address

destination logical address is

 

 

 

 

 

 

 

 

 

expected to be the default

 

 

 

 

 

 

 

 

 

254 value

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7.6.7 Command Packet Cyclic Redundancy Check

The header and data part of an RMAP packet are protected from errors by the use of an 8 bit CRC code. The header and data CRC is formed using the CRC-8 code used in ATM (Asynchronous

Transfer Mechanism). CRC-8 has the polynomial: X 8 + X 2 + X 1 +1 with a starting value of 00h.

Command packets received by the SpaceWire router which have an invalid header CRC are discarded and the Invalid Header CRC bit is set in the configuration port register.

7.6.8 Local Source Path Address

The configuration reply packet shall be routed out of the router port the packet arrived on. For example, if SpaceWire port 1 passed a configuration command to the configuration port then the reply packet is returned to port 1.

Preliminary

76

Page 76
Image 76
Atmel SpW-10X user manual Command Packet Cyclic Redundancy Check, Local Source Path Address