PM7375-SC datasheet(83/430 Pages) PMC

83 / 430 page

PM7375 LASAR-155

DATA SHEET

PMC-931127

ISSUE 6

LOCAL ATM SAR & PHYSICAL LAYER

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

Each queue element is a sixteen bit structure consisting of a TDR and several

Status bits. Status bits are used by the TRM to inform the PCI Host on the success

of packet segmentation. Please refer below.

9.14.4.2

Fig. 9.11 TDRF Queue Elements

TDR[13:0]

STATUS[1:0]

Bit 0

Bit 15

Status

Descriptor

Segmentation successful, last/only buffer of packet.

Segmentation successful, buffer of partial packet.

Segmentation failed due to unprovisioned VC or Max

SDU error.

If transmission of a packet over an unprovisioned VC or transmission of an

oversized SDU packet is attempted, the TRM will abort transmission before the first

cells has been transmitted and will attach the packet's TDR to the TDRF Queue with

the segmentation failed status. In addition if a VC is unprovisioned and it is currently

segmenting a packet, the current TDR of the packet will be returned with a

segmentation failed status. Note, only the first TDR of the linked list of TDRs is

attached to the TDRF Queue. The PCI Host can follow the Host Next TD Pointer

and the PCID Next TD Pointer in the TD to recover all the buffers associated with

the packet. Please refer to the Transmit Descriptor section for a detailed description

of these pointers.

PM7375-SC датащи(PDF) 83 Page - PMC-Sierra, Inc