PM7366-PI datasheet(69/286 Pages) PMC

69 / 286 page

RELEASED

PM7366 FREEDM-8

DATA SHEET

PMC-1970930

ISSUE 4

FRAME ENGINE AND DATA LINK MANAGER

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA,INC., AND FOR ITS CUSTOMERS’ INTERNAL USE

Field

Description

The Priority bit is set by the host to indicate the priority of the

associated packet in a two level quality of service scheme.

Packets with its P bit set high are queued in the high priority

queue in the TMAC. Packets with the P bit set low are queued in

the low priority queue. Packets in the low priority queue will not

begin transmission until the high priority queue is empty.

The V bit is used to indicate that the TMAC Next TD Pointer field

is valid. When set to logic 1, the TMAC Next TD Pointer[13:0]

field is valid. When V is set to logic 0, the TMAC Next TD

Pointer[13:0] field is invalid. The V bit is used by the host to

reclaim data buffers in the event that data presented to the

TMAC is returned to the host due to a channel becoming

unprovisioned. The V bit is expected to be initialised to logic 0 by

the host.

The More (M) bit is used by the host to support packets that

require multiple TDs. If M is set to logic 1, the current TD is just

one of several TDs for the current packet. If M is set to logic 0,

this TD either describes the entire packet (in the single TD

packet case) or describes the end of a packet (in the multiple TD

packet case).

Note: When M is set to logic 1, the only valid value for CE is

logic 0.

The Chain End (CE) bit is used by the host to indicate the end of

a linked list of TDs presented to the TMAC. The linked list can

contain one or more packets as delineated by the M bit (see

above). When CE is set to logic 1, the current TD is the last TD

of a linked list of TDs. When CE is set to logic 0, the current TD

is not the last TD of a linked list. When the current TD is not the

last of the linked list, the Host Next TD Pointer[13:0] field is valid,

otherwise the field is not valid.

Note: When CE is set to logic 1, the only valid value for M is

logic 0.

Note: When presenting raw (i.e. unpacketised) data for

transmission, the host should code the M and CE bits as for a

single packet chain, i.e. M=1, CE=0 for all TDs except the last in

the chain and M=0, CE=1 for the last TD in the chain.

TCC[6:0]

The Transmit Channel Code (TCC[6:0]) field is used by the host

to indicate with which channel a TD is associated. All TD in a

chain must be associated with the same channel, i.e. have this

field set to the same value.

PM7366-PI データシート(PDF) 69 Page - PMC-Sierra, Inc

PM7366-PI データシート(HTML) 69 Page - PMC-Sierra, Inc

Html Pages

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 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

データシートダウンロード