DEC/Intel 21140/21142/21143/21145 and clones 10/100
dc* at pci?
dc* at cardbus?
amphy* at mii?
bmtphy* at mii?
dcphy* at mii?
icsphy* at mii?
lxtphy* at mii?
mtdphy* at mii?
nsphy* at mii?
nsphyter* at mii?
sqphy* at mii?
tqphy* at mii?
driver provides support for several
PCI, Mini PCI, and CardBus Fast Ethernet adapters and embedded controllers
based on the following chipsets:
- DEC 21140 PCI
- DEC/Intel 21143 PCI and CardBus
- Intel 21145 PCI
- Macronix 98713, 98713A, 98715, 98715A, 98725, 98727 and 98732
- Davicom DM9100, DM9102, and DM9102A
- ASIX Electronics AX88140A and AX88141
- ADMtek AL981 Comet, AN983 Centaur-P and ADM9511/ADM9513 Centaur-II
- ADMtek AN985 Centaur-C CardBus
- Lite-On 82c168 and 82c169 PNIC
- Lite-On/Macronix 82c115 PNIC II
- Xircom X3201-based CardBus
All of these chips have the same general register layout, DMA descriptor format
and method of operation. All of the clone chips are based on the 21143 design
with various modifications. (The 21140 is an older version of the 21143.) The
21143 itself has support for 10baseT, BNC, AUI, MII and symbol media
attachments, 10 and 100Mbps speeds in full or half duplex, and built-in NWAY
autonegotiation. The 21143 also offers several receive filter programming
options including perfect filtering, inverse perfect filtering and hash table
filtering. The 21145 seems to be 10Mbps only and has an additional
(unsupported) HomePNA PHY.
Some clone chips duplicate the 21143 fairly closely while others only maintain
superficial similarities. Some support only MII media attachments. Others use
different receiver filter programming mechanisms. At least one supports only
chained DMA descriptors (most support both chained descriptors and
contiguously allocated fixed size rings). Some chips (especially the PNIC)
also have peculiar bugs. The
its best to provide generalized support for all of these chipsets in order to
keep special case code to a minimum.
These chips are used by many vendors, which makes it difficult to provide a
complete list of all supported cards. The following NICs are known to work
driver at this time:
- Digital DE500-BA 10/100 (21143, non-MII)
- Built-in DE500-BA on DEC Alpha workstations (21143, non-MII)
- Built-in Ethernet on Linksys EtherFast 10/100 Instant GigaDrive (DM9102,
- Kingston KNE100TX (21143, MII)
- D-Link DFE-570TX (21143, MII, quad port)
- NDC SOHOware SFA110A (98713A)
- NDC SOHOware SFA110A Rev B4 (98715AEC-C)
- SVEC PN102-TX (98713)
- CNet Pro120A (98715A or 98713A) and CNet Pro120B (98715)
- Compex RL100-TX (98713 or 98713A)
- Linksys LNE100TX (PNIC 82c168, 82c169)
- NetGear FA310-TX Rev. D1, D2 or D3 (PNIC 82c169)
- Matrox FastNIC 10/100 (PNIC 82c168, 82c169)
- Kingston KNE110TX (PNIC 82c169)
- Linksys LNE100TX v2.0 (PNIC II 82c115)
- Jaton XpressNet (Davicom DM9102)
- Alfa Inc GFC2204 (ASIX AX88140A)
- CNet Pro110B (ASIX AX88140A)
- Linksys LNE100TX v4.x (ADMtek AN983 Centaur-P)
- Xircom CardBus, including RealPort models (Xircom X3201)
- IBM EtherJet 10/100 CardBus (Intel 21143)
- Accton EN1217 (98715) and EN2242 (ADMtek Centaur)
- Mototech ME316 (ADMtek Centaur)
- Conexant LANfinity RS7112 Mini PCI
driver supports the following media
- Enable autoselection of the media type and options. The user can manually
override the autoselected mode by adding media options to the
Note: the built-in NWAY autonegotiation on the original PNIC 82c168 chip is
horribly broken and is not supported by the
dc driver at this time: the chip will
operate in any speed or duplex mode, however these must be set manually.
The original 82c168 appears on very early revisions of the Linksys
LNE100TX and Matrox FastNIC.
- Set 10Mbps operation. The mediaopt option
can also be used to enable full-duplex
operation. Not specifying full duplex
implies half-duplex mode.
- Set 100Mbps (Fast Ethernet) operation. The
mediaopt option can also be used to
enable full-duplex operation. Not
specifying full duplex implies
driver supports the following media
- Force full duplex operation. The interface will operate in half duplex
mode if this media option is not specified.
Note that the 100baseTX media type may not be available on certain Intel 21143
adapters which support 10Mbps media attachments only. The Intel 21145 supports
10Mbps half-duplex only.
For more information on configuring this device, see
- dc0: couldn't map ports/memory
- A fatal initialization error has occurred.
- dc0: couldn't map interrupt
- A fatal initialization error has occurred.
- dc0: watchdog timeout
- A packet was queued for transmission and a transmit command was issued,
however the device failed to acknowledge the transmission before a timeout
expired. This can happen if the device is unable to deliver interrupts for
some reason, or if there is a problem with the network connection
- dc0: no memory for rx list
- The driver failed to allocate an mbuf for the receiver ring.
- dc0: TX underrun -- increasing TX threshold
- The device generated a transmit underrun error while attempting to DMA and
transmit a packet. This happens if the host is not able to DMA the packet
data into the NIC's FIFO fast enough. The driver will dynamically increase
the transmit start threshold so that more data must be DMAed into the FIFO
before the NIC will start transmitting it onto the wire.
- dc0: TX underrun -- using store and forward mode
- The device continued to generate transmit underruns even after all
possible transmit start threshold settings had been tried, so the driver
programmed the chip for store and forward mode. In this mode, the NIC will
not begin transmission until the entire packet has been transferred into
its FIFO memory.
ADMtek AL981 and AL983 data
ASIX Electronics AX88140A and
AX88141 data sheets,
Davicom DM9102 data sheet,
Intel 21143 Hardware Reference
Macronix 98713/A, 98715/A and
98725 data sheets,
Macronix 98713/A and 98715/A app
device driver first appeared in
was added in OpenBSD 2.7
driver was written by
and ported to OpenBSD
The Macronix application notes claim that in order to put the chips in normal
operation, the driver must write a certain magic number into the CSR16
register. The numbers are documented in the app notes, but the exact meaning
of the bits is not.
The 98713A seems to have a problem with 10Mbps full duplex mode. The transmitter
works but the receiver tends to produce many unexplained errors leading to
very poor overall performance. The 98715A does not exhibit this problem. All
other modes on the 98713A seem to work correctly.
The original 82c168 PNIC chip has built-in NWAY support which is used on certain
early Linksys LNE100TX and Matrox FastNIC cards, however it is horribly broken
and difficult to use reliably. Consequently, autonegotiation is not currently
supported for this chipset: the driver defaults the NIC to 10baseT half
duplex, and it's up to the operator to manually select a different mode if
necessary. (Later cards use an external MII transceiver to implement NWAY
autonegotiation and work correctly.)
driver programs 82c168 and 82c169 PNIC
chips to use the store and forward setting for the transmit start threshold by
default. This is to work around problems with some NIC/PCI bus combinations
where the PNIC can transmit corrupt frames when operating at 100Mbps, probably
due to PCI DMA burst transfer errors.
The 82c168 and 82c169 PNIC chips also have a receiver bug that sometimes
manifests during periods of heavy receive and transmit activity, where the
chip will improperly DMA received frames to the host. The chips appear to
upload several kilobytes of garbage data along with the received frame data,
dirtying several RX buffers instead of just the expected one. The
driver detects this condition and will
salvage the frame, however it incurs a serious performance penalty in the
The PNIC chips also sometimes generate a transmit underrun error when the driver
attempts to download the receiver filter setup frame, which can result in the
receive filter being incorrectly programmed. The
driver will watch for this condition and
requeue the setup frame until it is transferred successfully.
The ADMtek AL981 chip (and possibly the AN983 as well) has been observed to
sometimes wedge on transmit: this appears to happen when the driver queues a
sequence of frames which cause it to wrap from the end of the transmit
descriptor ring back to the beginning. The
driver attempts to avoid this condition
by not queuing any frames past the end of the transmit ring during a single
invocation of the
() routine. This
workaround has a negligible impact on transmit performance.
() function does not currently
run for ASIX boards, meaning cable disconnects and reconnects can go
unnoticed. The AX88140A and AX88141 data sheets indicate that they don't have
RX or TX state registers (the bits are reserved). Therefore, we can't seem to
reliably detect when the adapter is idle.
The Davicom interfaces require a grossly high PCI latency timer value to
function properly. This means when a Davicom adapter is present in the
machine, it is given an unfairly high amount of bandwidth on the PCI bus,
unnecessarily taking time away from other devices. Therefore, Davicom network
cards are not recommended for use with OpenBSD
careful; some motherboards have Davicom interfaces built-in.