參數(shù)資料
型號(hào): AM79C940KCW
廠商: ADVANCED MICRO DEVICES INC
元件分類: 微控制器/微處理器
英文描述: Media Access Controller for Ethernet (MACE)
中文描述: 4 CHANNEL(S), 10M bps, LOCAL AREA NETWORK CONTROLLER, PQFP10
封裝: PLASTIC, QFP-100
文件頁(yè)數(shù): 57/122頁(yè)
文件大?。?/td> 914K
代理商: AM79C940KCW
第1頁(yè)第2頁(yè)第3頁(yè)第4頁(yè)第5頁(yè)第6頁(yè)第7頁(yè)第8頁(yè)第9頁(yè)第10頁(yè)第11頁(yè)第12頁(yè)第13頁(yè)第14頁(yè)第15頁(yè)第16頁(yè)第17頁(yè)第18頁(yè)第19頁(yè)第20頁(yè)第21頁(yè)第22頁(yè)第23頁(yè)第24頁(yè)第25頁(yè)第26頁(yè)第27頁(yè)第28頁(yè)第29頁(yè)第30頁(yè)第31頁(yè)第32頁(yè)第33頁(yè)第34頁(yè)第35頁(yè)第36頁(yè)第37頁(yè)第38頁(yè)第39頁(yè)第40頁(yè)第41頁(yè)第42頁(yè)第43頁(yè)第44頁(yè)第45頁(yè)第46頁(yè)第47頁(yè)第48頁(yè)第49頁(yè)第50頁(yè)第51頁(yè)第52頁(yè)第53頁(yè)第54頁(yè)第55頁(yè)第56頁(yè)當(dāng)前第57頁(yè)第58頁(yè)第59頁(yè)第60頁(yè)第61頁(yè)第62頁(yè)第63頁(yè)第64頁(yè)第65頁(yè)第66頁(yè)第67頁(yè)第68頁(yè)第69頁(yè)第70頁(yè)第71頁(yè)第72頁(yè)第73頁(yè)第74頁(yè)第75頁(yè)第76頁(yè)第77頁(yè)第78頁(yè)第79頁(yè)第80頁(yè)第81頁(yè)第82頁(yè)第83頁(yè)第84頁(yè)第85頁(yè)第86頁(yè)第87頁(yè)第88頁(yè)第89頁(yè)第90頁(yè)第91頁(yè)第92頁(yè)第93頁(yè)第94頁(yè)第95頁(yè)第96頁(yè)第97頁(yè)第98頁(yè)第99頁(yè)第100頁(yè)第101頁(yè)第102頁(yè)第103頁(yè)第104頁(yè)第105頁(yè)第106頁(yè)第107頁(yè)第108頁(yè)第109頁(yè)第110頁(yè)第111頁(yè)第112頁(yè)第113頁(yè)第114頁(yè)第115頁(yè)第116頁(yè)第117頁(yè)第118頁(yè)第119頁(yè)第120頁(yè)第121頁(yè)第122頁(yè)
AMD
57
Am79C940
USER ACCESSIBLE REGISTERS
The following registers are provided for operation of the
MACE device. All registers are 8-bits wide unless other-
wise stated. Note that all reserved register bits should
be written as zero.
Receive FIFO (RCVFIFO)
(REG ADDR 0)
RCVFIFO [15–0]
This register provides a 16-bit data path from the Re-
ceive FIFO. Reading this register will read one word/
byte from the Receive FIFO. The RCVFIFO should only
be read when Receive Data Transfer Request
(
RDTREQ
) is asserted. If the RCVFIFO location is read
before 64-bytes are available in the RCVFIFO (or
12-bytes in the case that LLRCV is set in the Receive
Frame Control register),
DTV
will not be returned. Once
the 64-byte threshold has been achieved and
RDTREQ
is asserted, the de-assertion of
RDTREQ
does not pre-
vent additional data from being read from the RCVFIFO,
but indicates the number of additional bytes which are
present, before the RCVFIFO is emptied, and
subsequent reads will not return
DTV
(see the FIFO
Sub-System section for additional details). Write opera-
tions to this register will be ignored and
DTV
will not be
returned.
Byte transfers from the RCVFIFO are supported, and
will be fully aligned to the target memory architecture,
defined by the BSWP bit in the BIU Configuration Con-
trol register. The Byte Enable inputs (
BE
1–0) will define
which half of the data bus should be used for the trans-
fer. The external host/controller will be informed that the
last byte/word of data in a receive frame is being read
from the RCVFIFO, when the MACE device asserts the
EOF
signal.
Transmit FIFO (XMTFIFO)
(REG ADDR 1)
XMTFIFO [15–0]
This register provides a 16-bit data path to the Transmit
FIFO. Byte/word data written to this register will be
placed in the Transmit FIFO. The XMTFIFO can be writ-
ten at any time the Transmit Data Transfer Request
(
TDTREQ
) is asserted. The de-assertion of
TDTREQ
does not prevent data being written to the XMTFIFO, but
indicates the number of additional write cycles which
can take place, before the XMTFIFO is filled, and
subsequent writes will not return
DTV
(see the FIFO
Sub-System section for additional details). Read opera-
tions to this register will be ignored and
DTV
will not be
returned.
Byte transfers to the XMTFIFO are supported, and ac-
cept data from the source memory architecture to en-
sure the correct byte ordering for transmission, defined
by the BSWP bit in the MAC Configuration Control regis-
ter. The Byte Enable inputs (
BE
1–0) will define which
half of the data bus should be used for the transfer. The
use of byte transfers have implications on the latency
time provided by the XMTFIFO (see the FIFO Sub-
Systemsection for additional details). The external host/
controller must indicate the last byte/word of data in a
transmit frame is being written to the XMTFIFO, by as-
serting the
EOF
signal.
Transmit Frame Control (XMTFC)
The Transmit Frame Control register is latched inter-
nally on the last write to the Transmit FIFO for each indi-
vidual packet, when
EOF
is asserted. This permits
automatic transmit padding and FCS generation on a
packet-by-packet basis.
(REG ADDR 2)
DRTRY
RES
RES
DXMTFCS
RES
RES
APAD XMT
RES
Bit
Name
Description
Bit 7
DRTRY
Disable Retry. When DRTRY is
set, the MACE device will provide
a single transmission attempt for
the packet, all further retries will
be suspended. In the case of a
collision during the attempt, a
Retry Error (RTRY) will be re-
ported in the Transmit Status.
With DRTRY cleared, the MACE
device will attempt up to 15 re-
tries (16 attempts total) before in-
dicating a Retry Error. DRTRY is
cleared by activation of the
RE-
SET
pin or SWRST bit. DRTRY is
sampled during the transmit
process when a collision occurs.
DRTRY should not be changed
whilst data remains in the Trans-
mit FIFO since this may cause an
unpredictable retry response to a
collision. Once the Transmit
FIFO is empty, DRTRY can be
reprogrammed.
Reserved. Read as zeroes. Al-
ways write as zeroes.
Disable Transmit FCS. When
DXMTFCS = 0 the transmitter
will generate and append an FCS
to the transmitted frame. When
DXMTFCS = 1, no FCS will be
appended to the transmitted
frame, providing that APAD XMT
is also clear. If APAD XMT is set,
the calculated FCS will be ap-
pended to the transmitted mes-
sage regardless of the state of
DXMTFCS.
The
DXMTFCS for each frame is pro-
grammed when
EOF
is asserted
to transfer the last byte/word for
the transmit packet to the FIFO.
DXMTFCS
is
Bit 6–4 RES
Bit 3
DXMTFCS
value
of
cleared
by
相關(guān)PDF資料
PDF描述
AM79C960 PCnetTM-ISA Single-Chip Ethernet Controller
AM79C960KC PCnetTM-ISA Single-Chip Ethernet Controller
AM79C960KCW PCnetTM-ISA Single-Chip Ethernet Controller
AM79C961AKCW PCnet ⑩-ISA II Jumperless, Full Duplex Single-Chip Ethernet Controller for ISA
AM79C961AKC PCnet ⑩-ISA II Jumperless, Full Duplex Single-Chip Ethernet Controller for ISA
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C940KI 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LAN Node Controller
AM79C940KI/W 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LAN Node Controller
AM79C940VC 制造商:未知廠家 制造商全稱:未知廠家 功能描述:LAN Node Controller
AM79C940VC/W 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Media Access Controller for Ethernet (MACE⑩)
AM79C940VCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Media Access Controller for Ethernet (MACE)