pnx1700 NXP Semiconductors, pnx1700 Datasheet - Page 706

• Manufacturer Part Number: pnx1700
• Description: Connected Media Processor
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Volume 1 of 1
5. LAN100 Functions
PNX17XX_SER_1
Preliminary data sheet
5.1.1 Overview
5.1 MMIO Interface
word contains flags returned by the LAN100 and flags generated by the Transmit
Datapath reflecting the status of the transmission.
the StatusInfo word.
Table 11: Transmit Status Information Word
For multi-fragment packets, the value of the LateCollision, ExcessiveCollision,
ExcessiveDefer, Defer and CollissionCount bits in all but the last fragment in the
packet will be 0. The status of the last fragment in the packet will copy the value for
these bits from the MII Interface. All fragment statuses will have valid Error,
NoDescriptor and Underrun bits.
This section defines the functions of the LAN100. After introducing the DMA concepts
and giving a description of the basic transmit and receive functions, this section
covers such advanced features as flow control, receive filtering, and the like.
The LAN100 MMIO interface is connected to the DCS system control bus so that the
host registers are visible from the CPU. The MMIO interface allows device driver
software on the CPU to interact with the LAN100.
The MMIO interface has a 32-bit datapath and an address aperture of 4KB. It only
supports word accesses.
Bit
31
30
29
28
27
26
25
24:21 CollisionCount
20:0
Name
Error
NoDescriptor
Underrun
LateCollision
ExcessiveCollision Indicates this packet exceeded the maximum collision limit and
ExcessiveDefer
Defer
-
Rev. 1 — 17 March 2006
Chapter 23: LAN100 — Ethernet Media Access Controller
Function
An error occurred during transmission. This is a logic OR of
LateCollision, ExcessiveCollision and ExcessiveDefer.
The Tx stream is interrupted, because a descriptor is not
available.
A Tx underrun occurred because the adapter did not produce
transmit data or the adapter is not accepting statuses.
An Out-of-window-collision was seen, causing packet abort.
(See TSV[29].)
was aborted. (See TSV[28].)
This packet incurred deferral beyond the maximum deferral limit
and was aborted. (See TSV[27].)
This packet incurred deferral, because the medium was
occupied. This is not an error unless excessive deferral occurs.
(See TSV[26].)
The number of collisions this packet incurred, up to the
Retransmission Maximum. (See TSV[19:16].)
Unused
Table 1 on page 23-6
lists the LAN100 registers.
Table 11
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
PNX17xx Series
lists the bit definitions in
23-33