Datasheet

TSB12LV32 Data Formats
71
SGLS139B − October 2003 − Revised April 2004 TSB12LV32-EP
Table 7−2. Block Transmit Format Functions
FIELD NAME DESCRIPTION
spd The Spd field indicates the speed at which the current packet is to be sent. 00 = 100 Mbps, 01 = 200 Mbps, and
10 = 400 Mbps, and 11 is undefined for this implementation.
tLabel The tLabel field is the transaction label, which is a unique tag for each outstanding transaction between two nodes. This
field is used to pair up a response packet with its corresponding request packet.
rt The rt field is the retry code for the current packet: 00 = new, 01 = retry_X, 10 = retryA, and 11 = retryB.
tCode tCode is the transaction code for the current packet (see Table 6−10 of the IEEE 1394-1995 standard).
priority The priority level for the current packet. For cable implementation, the value of the bits must be zero. For backplane
implementation, see clauses 5.4.1.3 and 5.4.2.1 of the IEEE 1394-1995 standard.
destinationID The destinationID field is the concatenation of the 10-bit bus number and the 6-bit node number that forms the node
address to which the current packet is being sent.
destination OffsetHigh,
destination OffsetLow
The concatenation of the destination OffsetHigh and the destination OffsetLow fields addresses a quadlet in the
destination node address space. This address must be quadlet aligned (modulo 4). The upper 4 bits of the destination
OffsetHigh field are used as the response code for lock-response packets and the remaining bits are reserved.
dataLength The dataLength filed contains the number of bytes of data to be transmitted in the packet.
extended_tCode The block extended_tCode to be performed on the data in the current packet (see Table 6−11 of the IEEE 1394-1995
standard).
block data The block data field contains the data to be sent. If dataLength is 0, no data should be written into the FIFO for this field.
Regardless of the destination or source alignment of the data, the first byte of the block must appear in byte 0 of the first
quadlet.
7.1.3 Quadlet Receive
The quadlet-receive format through the FIFO (GRF) is shown in Figure 7−3 and is described in Table 7−3. The
first quadlet (trailer) contains the packet-reception status that is added by the TSB12LV32. The first 16 bits
of the second quadlet contain the destination node and bus ID, and the remaining 16 bits contain
packet-control information. The first 16 bits of the third quadlet contain the node and bus ID of the source, and
the remaining 16 bits of the third quadlet and the fourth quadlet contain the 48-bit, quadlet-aligned destination
offset address. The last quadlet contains data that is used by write requests and read responses. For read
requests and write responses, the quadlet data field is omitted.
The quadlet-receive format through the DM is shown in Figure 7−4 and is described in Table 7−3. This format
is similar to the quadlet receive format for the TSB12LV31(GPLynx). The first 16 bits of the first quadlet contain
the destination node and bus ID and the remaining 16 bits contain packet-control information. The first 16 bits
of the second quadlet contain the node and bus ID of the source, and the remaining 16 bits of the second and
third quadlets contain the 48 bit, quadlet-aligned destination offset address for read requests and write
requests, but contain the 4-bit rCode for read responses and write responses. The fourth quadlet contains data
that is used by write requests and read responses. For read requests and write responses, the quadlet data
field is omitted. The last quadlet (trailer) contains the packet-reception status that is added by the TSB12LV32.
3210 765411109815141312 19181716 20 21 31302928272625242322
spdnumofQuadlets
sourceID
destination OffsetHigh
00
00 0 ackCode 00 0000
prioritytCoderttLabel
destinationID
destination OffsetLow
quadlet data (write requests and read responses only, omitted for write responses and read requests)
Figure 7−3. GRF Quadlet-Receive Format