PDI1394L21 データシートの表示（PDF） - Philips Electronics

部品番号

コンポーネント説明

一致するリスト

PDI1394L21

1394 full duplex AV link layer controller

Philips Electronics 

Philips Semiconductors

1394 full duplex AV link layer controller

Preliminary specification

PDI1394L21

Table 5. Asynchronous Receive Fields

Field Name

Description

destinationID

This field is the concatenation of busNumbers (or all ones for “local bus”) and nodeNumbers (or all ones for

broadcast) for this node.

tLabel

This field is the transaction label, which is used to pair up a response packet with its corresponding request packet.

rt

The retry code for this packet. 00=retry1, 01=retryX, 10=retryA, 11=retryB.

tCode

The transaction code for this packet.

priority

The priority level for this packet (0000 for cable environment).

sourceID

This is the node ID of the sender of this packet.

destinationOffsetHigh, The concatenation of these two field addresses a quadlet in this node’s address space.

destinationOffsetLow

rCode

Response code for response packets.

quadlet data

For quadlet write requests and quadlet read responses, this field holds the data received.

dataLength

The number of bytes of data to be received in a block packet.

extendedTcode

If 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 received. If dataLength=0, no data will be written into the FIFO for this field. Regardless of the destination

or source alignment of the data, the first byte of the block will 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.

u

Unsolicited response tag bit. This bit is set to one (1) if the received response was unsolicited.

ackSent

This field contains the acknowledge code that the link layer returned to the sender of the received packet. For

packets that do not need to be acknowledged (such as broadcasts) the field contains the acknowledge value that

would have been sent if an acknowledge had been required. The values for this field are listed in Table 6 (they also

can be found in the IEEE 1394 standard).

Table 6. Acknowledge codes

Code

0001

0010

0100

0101

0110

1101

Name

ack_complete

ack_pending

ack_busy_X

ack_busy_A

ack_busy_B

ack_data_error

Description

The node has successfully accepted the packet. If the packet was a request subaction, the

destination node has successfully completed the transaction and no response subaction shall follow.

The node has successfully accepted the packet. If the packet was a request subaction, a response

subaction will follow at a later time. This code shall not be returned for a response subaction.

The packet could not be accepted. The destination transaction layer may accept the packet on a

retry of the subaction.

The packet could not be accepted. The destination transaction layer will accept the packet when the

node is not busy during the next occurrence of retry phase A.

The packet could not be accepted. The destination transaction layer will accept the packet when the

node is not busy during the next occurrence of retry phase B.

The node could not accept the block packet because the data field failed the CRC check, or because

the length of the data block payload did not match the length contained in the dataLength field. This

code shall not be returned for any packet that does not have a data block payload.

1110

0000, 0011,

0111 – 1100,

and 1111

ack_type_error

reserved

A field in the request packet header was set to an unsupported or incorrect value, or an invalid

transaction was attempted (e.g., a write to a read-only address).

This revision of the AV Link will not generate other acknowledge codes, but may receive them from

newer (1394 A) links. In that case, these new values will show up here.

NOTE:

1. Upon receipt of a broadcast packet, if any ACK code other than ACK_DATA_ERROR is produced, asume packet receipt was OK.

ACK_DATA ERROR indicates the packet was received with an error, appropriate steps should be taken to ignore the packet and inform the

sending node of the error.

1999 Aug 06

18

Share Link: