SpW-10X

Ref.:

UoD_SpW-10X_

SpaceWire Router

 

UserManual

Issue:

3.4

User Manual

Date:

11th July 2008

 

 

 

In Figure 7-9 the format of the reply to a Read-Modify-Write command is illustrated. The first byte received by the SpaceWire router configuration logic is the port address followed by the destination logical address. Fields which are depicted in bold text are expected values. Fields which are shaded are optional. Note that the reply is always sent out of the same port as the command was received on. The Source Path Address should not include the output port of the router being commanded as the reply will be automatically sent out of the same port that the command arrived on. See section 7.6.8.

 

 

 

First byte transmitted

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Source Path Address

Source Path Address

Source Path Address

 

 

 

 

 

 

 

 

 

 

 

 

 

Source Logical Address

Protocol Identifier

Packet Type, Command,

Status

 

 

01h

 

Source Path Addr Len

 

 

 

 

 

 

 

 

 

 

Destination Logical Address

Transaction Identifier (MS)

Transaction Identifier (LS)

Reserved

 

 

 

FEh

 

 

 

 

 

 

 

00h

 

 

Data Length (MS)

Data Length

 

Data Length (LS)

Header CRC

 

 

00h

00h

 

 

04h

 

 

 

 

 

 

 

 

 

Data (MSB)

Data

 

 

Data

Data (LSB)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Data CRC

EOP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Last byte transmitted

 

 

 

 

 

 

 

 

 

 

 

Bits in Packet Type / Command / Source Path Address Length Byte

 

 

 

 

 

 

MSB

 

 

 

 

 

 

 

 

 

 

 

 

LSB

0

 

0

0

 

 

1

1

 

1

Source Path

 

Source Path

 

 

 

 

Address Length

 

Address Length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Packet Type

 

 

 

Command

 

 

Source Path Address Length

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 7-9 Read-Modify-Write Reply Packet Format

Table 7-13 Read-Modify-Write Reply Packet Fields

Field

Description

Bytes

 

 

 

Source Path

Optional source path addresses specified in the command packet. If no

0-12

Address

source path addresses are specified then the first byte will be the source

 

 

logical address.

 

 

 

 

Source Logical

The source logical address specified in the command packet. If source

1

Address

path addresses are not used then the source logical address is the

 

 

address of the return packet.

 

 

 

 

Protocol Identifier

The RMAP protocol identifier value 01h.

1

 

 

 

Command Byte

Read-Modify-Write reply command byte. The packet type bits in the

1

 

command byte indicate this packet is a response packet.

 

 

 

 

Status

The command status is returned in this field. The command status can be

1

 

command successful or an RMAP error code as defined in section 7.6.6.

 

 

 

 

Destination

The destination logical address is set to the default value FEh as the

1

 

 

 

 

 

 

 

Preliminary

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Atmel SpW-10X user manual FEh 00h