Atmel SpW-10X Preliminary57, SpaceWire Router, User Manual, Data Length MS, Data Length LS

SpW-10X	Ref.:	UoD_SpW-10X_
SpaceWire Router		UserManual
	Issue:	3.4
User Manual
	Date:	11th July 2008

Table 7-5 Read Single Address Characteristics
			Non-aligned access
Action	Supported/	Maximum number
	Not Supported	of bytes	accepted
			-
8-bit read	NS	-
			-
16-bit read	NS	-
			No
32-bit read	S	4
			-
64-bit read	NS	-
Word or byte address	32-bit aligned
Accepted Logical Addresses	0xFE
Accepted destination keys	0x20 at power on.
Accepted address ranges	0x00 0000 0000 – 0x00 0000 0109
Address Incrementation	No

The RMAP read single address command is supported in the SpaceWire router. The single address command is used to read a single 32 bit register location from the router registers.

In Figure 7-3 the format of a read single address 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.

First Byte Received

Config Port Address

00h

Destination Logical Address

Protocol Identifier

Packet Type, Command

Destination Key

FEh

01h

Source Path Addr Len

Source Path Address

Source Path Address

Source Path Address

Source Path Address

Source Logical Address

Transaction Identifier (MS)

Transaction Identifier (LS)

Extended Read Address

00h

Read Address (MS)

Read Address

Read Address

Read Address (LS)

00h

00h

Data Length (MS)

Data Length

Data Length (LS)

Header CRC

00h

00h

04h

EOP

Last Byte Received

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

MSB

LSB

0

1

0

0

1

0

Source Path

Source Path

Address Length

Address Length

Packet Type

Command

Source Path Address Length

Figure 7-3 Read Single Address Command Format

Preliminary57