Atmel SpaceWire Router SpW-10X User Manual

Ref.:   UoD_SpW-10X_ 

 

Issue:  3.4 

  

 

Date:  11

 

 

65

 

Command 

Byte  

Read incrementing address reply command byte. The packet type bits in the 

command byte indicate this packet is a reply packet. 

1 

Status  

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

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

1 

Destination 

logical 

address  

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

SpaceWire router does not have a logical address. 

1 

Transaction 

Identifier  

The transaction identifier identifies the command packet and reply packet with a 

unique number. The transaction identifier in the reply packet is copied from the 

command packet and returned in this field, so that the command and the 

corresponding reply have the same transaction identifier value. 

2 

Data 

Length  

The data length field is the number of bytes read from the router as specified in 

the data length field of the command packet. 

3 

Header 

CRC  

The header CRC used to detect errors in the header part of the command 

packet. See section 7.6.7 for CRC generation. 

1 

Data  

The data read from the registers in the device. The data is returned in 32 bit 

words starting from the address specified in read address in the command 

packet. 

>=4 

Data CRC  

The data CRC used to detect errors in the data part of the reply packet. See 

section 7.6.7 for CRC generation. 

1 

 

 

7.6.4  Read Modify Write Command 

The read-modify-write command characteristics are defined in Table 7-8. 

Action Supported/ 

Not Supported 

Maximum number 
of bytes 

Non-aligned access 
accepted 

8-bit read-modify-write 

NS 

- 

- 

16-bit read-modify-write 

NS 

- 

-