Sundance Spas ST201 - Manual (Page 10)

10
Sundance Technology ST201 PRELIMINARY draft 2
ACRONYMS AND GLOSSARY
LAN Local Area Network
MAC Media Access Control Layer, or a
device implementing the functions
of this layer (a Media Access Con-
troller)
PCI Peripheral Component Interface
NIC Network Interface Cards
FIFO First In First Out
MII Media Independent Interface
EPROM Erasable Programmable Read
Only Memory
EEPROM Electrically Erasable Programma-
ble Read Only Memory
LED Light Emitting Diode
PHY Physical Layer, or device imple-
menting functions of the Physical
Layer
CSMA/CD Carrier Sense Multiple Access
with Collision Detect
FCS Frame Check Sequence
SFD Start of Frame Delimiter
CRC Cyclic-Redundancy-Check
IP Internet Protocol
TFD Transmit Frame Descriptor
RFD Receive Frame Descriptor
DMA Direct Memory Access
ACPI Advanced Configuration and
Power Management
STANDARDS COMPLIANCE
The ST201 implements functionality compliant with
the following standards:
• IEEE 802.3u Fast Ethernet
• IEEE 802.3x Full Duplex Flow Control
• PCI Local Bus Revision 2.1
• ACPI Revision 1.0
FUNCTIONAL DESCRIPTION
The ST201 is composed of various functional
blocks as shown in Figure 1. An overview of the
functions performed by each block follows:
MEDIA ACCESS CONTROL
The MAC block implements the IEEE Ethernet
802.3u Media Access Control functions with 802.3x
Full Duplex and Flow Control enhancements. In
half duplex mode, the MAC implements the CSMA/
CD. Full duplex mode by definition does not utilize
CSMA/CD, allowing data to be transmitted on
demand. An optional flow control mechanism in full
duplex mode is provided via the 802.3x MAC Con-
trol PAUSE function. Additionally, the MAC also
performs the following functions in either half or full
duplex mode:
• Optional transmit FCS generation
• Padding to the minimum legal frame size
• Preamble and SFD generation
• Preamble and SFD removal
• Receive frame FCS checking and optional FCS
stripping
• Receive frame destination address matching
• Support for multicast and broadcast frame recep-
tion or rejection (via filtering)
• Selective InterFrame Gap to avoid capture effect
• MAC Loopback
The MAC is responsible for generation of hardware
signals to update the internal statistics counters.
MEDIA INDEPENDENT INTERFACE
The ST201 can support a variety of physical signal-
ing schemes via the IEEE 802.3u defined MII.
Through the MII, the ST201 supports Fast Ethernet
(such as 100BASE-TX) as well as the legacy
10BASE-T standard. The MII provides a general-
purpose interface between an 802.3u MAC and
various physical layer devices, and is comprised of
two independent components. The data interface
provides separate, 4-bit wide paths for receive and
transmit data, as well as independent clock and
control signals. The management interface is a
bidirectional, serial link that provides the ST201
access to registers residing within the physical
layer device. The host system controls the MII
management interface through the PhyCtrl regis-
ter.
Since the MII is independent of the signaling
method (100BASE-TX, 10BASE-T, etc.), it is possi-
ble to use it to support numerous Ethernet or Fast
Ethernet LAN types depending upon the availability
of MII-compliant PHY devices. The most widely
available PHY devices support both 10BASE-T
and 100BASE-TX through a single MII.
It is most likely that a physical layer device con-
nected to ST201’s MII will include implementation
of the 802.3u Auto-Negotiation function. For
instance, a PHY device may be able to auto-nego-
tiate between 10BASE-T and 100BASE-TX. A host
system attempting to determine link status should
check the Auto-Negotiation function contained in
the MII-based PHY device through the MII man-
agement interface of the ST201.