參數(shù)資料
型號(hào): AM79C930
廠商: Advanced Micro Devices, Inc.
英文描述: PCnet-Mobile Single-Chip Wireless LAN Media Access Controller
中文描述: PCnet -移動(dòng)單芯片無(wú)線局域網(wǎng)媒體接入控制器
文件頁(yè)數(shù): 54/161頁(yè)
文件大?。?/td> 691K
代理商: AM79C930
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)當(dāng)前第54頁(yè)第55頁(yè)第56頁(yè)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)第123頁(yè)第124頁(yè)第125頁(yè)第126頁(yè)第127頁(yè)第128頁(yè)第129頁(yè)第130頁(yè)第131頁(yè)第132頁(yè)第133頁(yè)第134頁(yè)第135頁(yè)第136頁(yè)第137頁(yè)第138頁(yè)第139頁(yè)第140頁(yè)第141頁(yè)第142頁(yè)第143頁(yè)第144頁(yè)第145頁(yè)第146頁(yè)第147頁(yè)第148頁(yè)第149頁(yè)第150頁(yè)第151頁(yè)第152頁(yè)第153頁(yè)第154頁(yè)第155頁(yè)第156頁(yè)第157頁(yè)第158頁(yè)第159頁(yè)第160頁(yè)第161頁(yè)
AMD
P R E L I M I N A R Y
54
Am79C930
CCA Result
(CHBSY Bit
of TIR26)
UBDCS
TCR28:1
URSSI
TCR28:0
Baud Detect Carrier
Sense Decision
RSSI >= RSSI
Lower Limit
0
0
0
1
1
1
1
1
1
0
1
1
0
0
1
1
1
1
don’t care
don’t care
don’t care
TRUE
FALSE
TRUE
TRUE
FALSE
FALSE
don’t care
yes
no
don’t care
don’t care
yes
no
yes
no
CHBSY = TRUE
CHBSY = TRUE
CHBSY = FALSE
CHBSY = TRUE
CHBSY = FALSE
CHBSY = TRUE
CHBSY = FALSE
CHBSY = FALSE
CHBSY = FALSE
The current CCA result is reported in the CHBSY bit
of TIR26.
A rising edge of CHBSY will set the Busy Channel
Found (BCF) bit of TIR5. This bit may serve as an inter-
rupt to the 80188 core, or the interrupt due to this bit may
be masked and the bit can be polled by the 80188 core.
The CCA result is also reported in the CHBSYC bit of
TIR4. This bit reports a change in state of the carrier
sense. This bit may serve as an interrupt to the 80188
core, or the interrupt due to this bit may be masked and
the bit can be polled by the 80188 core.
The current RSSI limit comparison test result may be
read from the RSALT bit (RSSI Above Limit) of TIR28.
The CCA result has no effect on the Transmit state ma-
chine operation. That is, if the CCA result is CHBSY =
TRUE and the TXS bit (Transmit Start) of TIR8 has been
set to a 1, then the transmit state machine will proceed
with execution of its transmission sequence. Determina-
tion of exactly when to begin transmission is the respon-
sibility of the firmware that sets the TXS bit of TIR8,
based upon input derived from the CHBSY bit of TIR26
and other considerations (such as NAV value, backoff
timer, etc.).
Automatic Antenna Diversity Logic
The TAI contains automatic antenna diversity logic that
relies on carrier sense determination in order to select a
satisfactory antenna for frame reception. The general
function of the antenna diversity logic is as follows:
The automatic antenna diversity logic switches the
ANTSLT and
ANTSLT
pins between two different anten-
nas repeatedly at a programmable periodic rate. Meas-
urements of signal strength and Baud Determination
testing are performed on each antenna. Antenna Diver-
sity Switching and test measurements continue until the
combination of the test outcomes dictates a stop to di-
versity switching. At such a point, a satisfactory antenna
has been found, antenna switching will cease and the
selected antenna will be used for reception until the Re-
ceive RESET (RXRES) bit of TIR16 is set, or until the
Receive Start (RXS) bit of TIR16 is set, or a hard reset,
or a soft reset. Baud detection tests continue during
antenna lock time, using the same periodicity (i.e.,
the dwell timer), even though antenna switching has
stopped. These baud tests provide input for the
CCA logic.
An antenna is deemed “satisfactory” when the combina-
tion of inputs to the Stop Diversity decision logic is
TRUE. The Stop Diversity decision is based upon the
value of one or two input conditions, where the user may
choose which conditions are examined. The following
are the two inputs that may be used for Stop
Diversity decisions:
One possible input to the Stop Diversity decision logic is
the Baud Detect for Stop Diversity determination as
described in the Baud Determinationsection and
summarized here. The Baud Detect for Stop Diversity
determination is made by making multiple measure-
ments of the separation between adjacent (and same–
direction) bit stream edge transitions (baud detect
tests), then comparing the measured rate of edge transi-
tions against programmed limits and tallying the number
of passes and failures of these tests, checking to see
that the total number of passed tests exceeds a given
lower limit, and finally, checking that the ratio of passes
to fails exceeds a given threshold ratio. If this final result
is TRUE, then the Baud Detect for Stop Diversity is con-
sidered to be “TRUE.”
Note that Baud Determination of Stop Diversity meas-
urements are made on a periodic basis where the period
and duty cycle of the measurements depends upon the
settings of the Antenna Diversity Timer (TCR4) and the
Baud Detect Start timer (TCR16). The Dwell Timer
never stops running (unless set to 0).
The second possible input to the Stop Diversity decision
logic is the result of a comparison of the RSSI converted
value against a pre-programmed lower limit. If the
measured RSSI input value exceeds the programmed
lower limit, then the result of this test is considered to
be TRUE.
The two tests mentioned above may be separately
selected/deselected to serve as inputs to the Stop
相關(guān)PDF資料
PDF描述
AM79C930VCW PCnet-Mobile Single-Chip Wireless LAN Media Access Controller
AM79C940VCW Media Access Controller for Ethernet (MACE)
AM79C940 Media Access Controller for Ethernet (MACE)
AM79C940JCW Media Access Controller for Ethernet (MACE)
AM79C940KCW Media Access Controller for Ethernet (MACE)
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AM79C930EVAL-HW 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Am79C930EVAL-HW - PCnet-Mobile Evaluation Kit
AM79C930VC/W 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-Mobile Single-Chip Wireless LAN Media Access Controller
AM79C930VCW 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:PCnet-Mobile Single-Chip Wireless LAN Media Access Controller
AM79C940 制造商:AMD 制造商全稱:Advanced Micro Devices 功能描述:Media Access Controller for Ethernet (MACE)