Datasheet

Internal Registers
20
SGLS139B − October 2003 − Revised April 2004TSB12LV32-EP
ASYNCHRONOUS HEADER FOR QUADLET 0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 29 30 31
28
TLABEL TCODE PRIORITYSPEED RT
BIT
NUMBER
BIT NAME FUNCTION DIR DESCRIPTION
0−13 RESERVED Reserved
14−15 SPEED Speed R/W Speed at which the Phy is to transmit the packet:
00 => S100
01 => S200
10 => S400
16−21 TLABEL Transaction label R/W Transaction label
22−23 RT Retry code R/W The retry code specifies whether this packet is a retry attempt and the retry protocol to
be followed by the destination node.
24−27 TCODE Transaction code R/W The transaction code specifies the packet format and the type of transaction that is to
be performed.
28−31 PRIORITY Priority field R/W Priority code (applies only to the backplane Phy)
2.2.14 Header1 Register at 3Ch
Header1 register contains the isochronous packet header (if multiple channels are supported) or the second
quadlet of an asynchronous packet header if the deivce is in automatic header insert transmit mode. If the
device is not in automatic-header-insert transmit mode or if it is in receive mode, this register is updated with
the second received header quadlet or the DM-supplied transmit header. This register powers up with all bits
reset to 0. For multiple isochronous channels (multiple isochronous packets within the same isochronous
cycle), this register contains the isochronous header of the second isochronous packet in the same format
as the header0 register if the device is in automatic-header-insert transmit mode. This register is write
protected such that it cannot be written to unless automatic-header-insert mode is enabled and the DM is in
transmit mode (i.e., DMHDR = 0 and DMRX = 0).
ISOCHRONOUS HEADER FOR QUADLET 1
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 29 30 31
28
PACKET DATA LENGTH TAG CHANNEL NUMBER TCODE SYNC BITS
BIT
NUMBER
BIT NAME FUNCTION DIR DESCRIPTION
0−15 PACKET DATA
LENGTH
Packet data length R/W Packet data length in bytes
16−17 TAG Tag field R/W The tag field provides a high-level label for the format of the data carried
by the isochronous packet.
18−23 CHANNEL
NUMBER
Channel number R/W Channel number field
24−27 TCODE Transmission code R/W Packet transaction code
28−31 SYNC BITS Synchronization
code
R/W An application-specific control field
ASYNCHRONOUS HEADER FOR QUADLET 1
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 29 30 31
28
DESTINATION ID
BIT
NUMBER
BIT NAME FUNCTION DIR DESCRIPTION
0−15 DESTINATION ID Destination ID R/W For asynchronous packets this field contains the destination node ID.
16−31 RESERVED Reserved