Philips Semiconductors

Preliminary specification

PDI1394L21

1394 full duplex AV link layer controller

1999 Aug 06

17

Table 3.

Block Transmit Field

Field Name

Description

spd, tLabel, rt, tCode, destinationID,

destinationOffsetHigh, destinationOffsetLow, rCode

See Table 2.

dataLength

The number of bytes of data to be transmitted in this packet

extendedTcode

The tCode indicates a lock transaction, this specifies the actual lock action to be

performed with the data in this packet.

block data

The data to be sent. If dataLength=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 the high order byte of the first quadlet.

padding

If the dataLength mod 4 is not zero, then zero-value bytes are added onto the end

of the packet to guarantee that a whole number of quadlets is sent.

12.5.1.4

Unformatted Transmit

The unformatted transmit format is shown in Figure 13. The first quadlet contains packet control information. The remaining quadlets contain

data that is transmitted without any formatting on the bus. No CRC is appended on the packet, nor is any data in the first quadlet sent. This is

used to send PHY configuration and Link-on packets. Note that the bit-inverted check quadlet must be included in the FIFO since the AV Link

core will not generate it.

spd

tLabel

1110

0000

29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0

unformatted packet data

SV00256

31 30

Figure 13. Unformatted Transmit Format

12.5.2

Asynchronous Receive Packet Formats

This section describes the asynchronous receive packet formats. Four basic asynchronous data packet formats and one confirmation format exist:

Table 4. Asynchronous Data Packet Formats

ITEM

FORMAT

USAGE

TRANSACTION CODE

1

No packet data

Quadlet read requests

4

1

No-packet data

Quadlet/block write responses

2

2

Quadlet packet

Qaudlet write requests

0

2

Quadlet packet

Quadlet read responses

6

Block read requests

5

Block write requests

1

3

Block Packet

Block read responses

7

Lock requests

9

Lock responses

4

Self-ID / PHY packet

Concatenated self-ID / PHY packets

5

Confirmation packet

Confirmation of packet transmission

8

Each packet format uses several fields. More information about most of these fields can be found in the 1394 specification.